Got anything else? How about something juicy?
This is the best we can do for you: SP1 will include the changes to Vista that Microsoft has agreed to after being pressured by the European Union's antitrust watchdog and then the US Department of Justice.
To get the EU's Competition Commission and its chief, Neelie Kroes, off its back last year, Microsoft bowed to criticism from the likes of Symantec and McAfee and promised to produce several application programming interfaces (API) that would give security vendors some access to the kernel of 64bit Vista, Microsoft's PatchGuard protection schemes notwithstanding. Also in SP1: another API that allows security companies to better integrate their products’ on-screen status features with Vista's built-in Windows Security Center.
This year, Microsoft did a similar dance with Justice and the states involved in the 2002 antitrust settlement over Google's complaints about search in Vista. Microsoft agreed to a number of changes in Vista, including one that lets user disable Vista's built-in search engine and switch to an alternate, such as Google Desktop.
Where can I get more information than what you've deigned to drop on me?
Your best bet - other to check back here - is the official white paper from Microsoft. (Note: A PDF of this will probably be stuck somewhere on the Microsoft site in the new future.)