Microsoft is apparently prepping Vista Fix Packs with fixes that have been expected for a Vista SP1.

The Vista Fix Packs where made available to Windows Server 2008 testers. The original source has disappeared, but ZDNet is all over this.

The Vista Fix Packs are supposed to improve speed of hibernate, sleep and resume and file transfers. The memory management is supposed to also get some optimizations.
Details on what the two Vista Fix Packs (Vista Performance and Reliability Pack) contain can be read on this post on ZDNet.

If and when Microsoft will release these Vista Fixes to the general public is not clear. It could also be that these will be rolled into a SP1 for Vista - only MS knows.

Photo from I4U Windows Vista Gadget Model Shoot with Candice. See more photos.