• OS X Lion Update 10.7.4 (Client) (692.68 MB)
• OS X Lion Update 10.7.4 (Client Combo) (1.4 GB)
• OS X Lion Update 10.7.4 (Server) Combo (1.49 GB)
• OS X Lion Update 10.7.4 (Server) Client (738.71 MB)
• Server Admin Tools 10.7.4 (212.4 MB)
  
  "About" Docs:
• About the OS X Lion v10.7.4 Update
• About the Lion Server v10.7.4 Update
• About the security content of OS X Lion v10.7.4
• About Server Admin Tools 10.7.4

See my list of Apple docs below for others related to this update and on fixes in 10.7.4.

  If you can wait, there's usually some feedback on updates in Apple's forums. Their OS X Lion Forum already has some 10.7.4 update problem reports. (May or may not be common.)
You can also check their Desktop and Notebooks forums for posts specific to your Mac model(s).

FYI: Some that had boot problems after 10.7.4 update had previously installed Apple's FIPS Cryptographic Module (v1.1 rel'd Apr 26) & Warren's tip of deleting its launch plist (/usr/sbin/fips/System/Library/LaunchDaemons/com.apple.fipspost.plist) was a fix for some.

(Although I have not bought Lion yet (nothing in 10.7.x I really need/want), I always prefer using DL/combo updaters instead of SU and did a clean reboot before applying an OS Update. (And of course had a backup/clone before updating.) I rarely use 3rd party addons/mods but if you do check the dev's site for any updates/notes on issues. Some also go so far as applying OS updates from a safe boot and/or Repairing Permissions before/after. Personally I do not run RP w/o a reason but do run a disk verify/check at times.)

  

• Security Update 2012-002 (Snow Leopard) (238.73 MB)
• Security Update 2012-002 Server (Snow Leopard) (258.11 MB)

Info on the D/L page simply says "Security Update 2012-002 is recommended for all users and improves the security of Mac OS X", but here's the doc with details About the security content of Security Update 2012-002 (doc also covers 10.7.4 update).
   Fixes noted for 10.6.x (Client/Server) are related to Security Framework, attacks on the confidentiality of SSL 3.0 and TLS 1.0, fixing issues in the directory server's message handling, fixes for vulnerabilities in ImageIO's handling of TIFF and libpng, fixes for libarchive, libsecurity, libxml, Quartz Composer, QuickTime (several), Ruby and Samba.

  

"About Safari 5.1.7
Lion
Safari 5.1.7 contains improvements to performance, stability, compatibility, and security, including changes that:

• Improve the browser's responsiveness when the system is low on memory
• Fix an issue that could prevent webpages from responding after using a pinch to zoom gesture
• Fix an issue that could affect websites using forms to authenticate users
• Disable versions of Adobe Flash Player that do not include the latest security updates and provide the option to get the current version from Adobe's website.

For more information, please visit: http://support.apple.com/kb/HT5271.
(That link is to the doc About Safari 5.1.7 for Lion/Snow Leopard that mentions only disabling out-of-date Flash Player versions)
For detailed information on the security content of this update, please visit: http://support.apple.com/kb/HT1222

Windows
Safari 5.1.7 contains improvements to performance, stability, compatibility, and security, including changes that:

• Improve the browser's responsiveness when the system is low on memory
• Fix an issue that could affect websites using forms to authenticate users

Lion System Requirements: v10.7.3
Snow Leopard System Requirements: v10.6.8
Windows: XP SP2, Vista or Windows 7"

Here's the doc with details About the security content of Safari 5.1.7.
(Fixes related to cross-site scripting, memory corruption and form input/state tracking.)
BTW: Browser updates may break 3rd party addons. Check the dev's site for any updates to them or notes on issues.

  

• Apple Remote Desktop 3.5.3 Client (included w/10.7.4)
• Portal 2 Update Released
• Photoshop CS6 dazzles with technical prowess and artistic inspiration
• Newer Technology Power2U USB Receptacle Review (audioholics)
  (BTW: A friend uses a Power2U behind his AVR rack to power 2 Cooling fans for the rear (*HOT*) area of an Onkyo NR3007. Much less cable clutter and the fans really help cool the Video Proc/HDMI board in that series, which have a history of failures.)

• About Safari 5.1.7
• About the security content of Safari 5.1.7
• About the Lion Server v10.7.4 Update
• About the OS X Lion v10.7.4 Update
• About the security content of OS X Lion v10.7.4 and Security Update 2012-002
• OS X Lion v10.7.4, Security Update 2012-002: Global DYLD launch variables no longer loaded
  
  
• About Apple Remote Desktop client 3.5.3 (included w/10.7.4)
• OS X Lion v10.7.3: User account passwords appear in log files for Legacy FileVault, and/or network home directories (fixed in 10.7.4)
• OS X Lion: After "Apply to enclosed items...", unable to change prefs, remove or save files, iPhoto & iTunes issues, Preview & TextEdit quit (fixed in 10.7.4)
• Lion Server: Server app unable to display Profile Manager settings after updating to Lion Server v10.7.3 (fixed in 10.7.4)
• Empty Trash may not delete folders if using network home directory (fixed in 10.7.4)
• Active Directory user not notified when password does not meet complexity requirements at login window (said fixed in 10.7.4)
• OS X Lion: Supported digital camera RAW formats (revised for 10.7.4)
  
  
• About file quarantine in OS X
• OS X: Starting up with the 32-bit or 64-bit kernel
• OS X 10.6 & earlier: Hiding or showing a window's toolbar
• OS X: How to quit an unresponsive application using Force Quit
• OS X: How to change the keyboard layout at the login window
• OS X: Changing the language shown in menus and dialogs
• Mac 101: Customize the Dock
  
  
• Logic Pro 9: Support resources
• Logic Pro 9: Frequently asked questions (FAQ)
• MainStage 2: Frequently asked questions (FAQ)
• Aperture 3: Frequently Asked Questions (FAQ)
• Final Cut Pro X: How to remove and reinstall Final Cut Pro X
• Final Cut Studio (2009): Compatible version of Cinema Tools for OS X Lion
  
  
• iPhoto for iOS 1.0.1: Sound Effects may disable audio playback
• iTunes Store: Associating a device or computer to your Apple ID
• iTunes Store & Mac App Store: Seeing your purchase history and order numbers
• iTunes Store movie rental usage rights in Canada
  
  
• Mac mini: About the DVI to VGA Adapter

• Sprint unveils versatile Tri-Fi hotspot
• Micron Airs New DDR4 DRAM For Tablets, Servers, Ultrabooks
• Twitter Downplays Breach That Exposed Passwords
• HP Laptop Launch Includes AMD 'Sleekbook'
• 20 years later, you can play (1992) Wolfenstein 3D online for free
• New TV remote controls respond to apps, speech and gestures

BTW - if you have a decent Sub setup, check out Underworld Awakening.
(Shook the walls in a small/sealed 10x12ft room with SW run hot.)