Bob Ward has posted a very thorough walk-through of the CU1 installation process.  He talks about some of the things they've improved with the setup of patches, and gives a bit of a teaser about about his next blog post, where he will discuss how they are making the patches update your local setup files, and keep them that way even if you uninstall the patch from the local instance (which smells a lot like the start of slipstreamed CUs/SPs).

http://blogs.msdn.com/psssql/archive/2008/09/26/welcome-to-sql-server-2008-patching.aspx