Windows Defender (on by default)
WinSAT (Windows Experience Index tool)
all components needed for mobile computers
Gadgets (CPU/RAM usage, time, calendar)
Games (no premium games)
.NET Framework 3.5.1
Windows Update and Security Center

A lot of stuff is removed to reduce the size of the image.

Some removed features:
Accessibility
BitLocker
PowerShell
Windows Help
asian languages and fonts (MS Office 2010 installs without errors)
Some rarely used fonts
Speech engine
Tablet features
IIS
Remote Desktop and Assistance
Sync Center
Windows Sounds, themes (aero presents)
Windows Easy Transfer

Some tweaks applied are:
Allow 3rd Party Themes
Allow windows Live Movie to import from network
Always Unload DLL
Disable Group Policy Synchronise
Disable Hibernation
Disable Search Online on Unknown File Extensions
Disable Shortcut Link Resolve
Disable Thumbnail Cache
Disable windows Error Reporting
Double Mouse Speed
Enable Boot Defrag
Enable DVD in Media Player
Enable MSI Service in Safe Mode
Faster Browsing in IE
Increase Icon Cache
Kill Services Quicker on Shutdown
Open NFO files with notepad
Remove 'HomeGroup' from Explorer
Remove 'Libraries' from Explorer
Remove 'Music' from Start Menu
Remove 'Pictures' from Start Menu
Remove Shortcut Suffix
Remove 'Videos' from Start Menu
Remove windows Mail Splash
Restore Previous Folder at Logon
Show 'Computer' on Desktop
Show Hidden Files/Folders
Speed-up Access to AVI Media Files
Unlimited Simultaneous Downloads