I haven't heard anything about a drastic change to the test, but it's possible (likely) that new questions were added to the pool that cover SP1 or are more applicable to administration rather than user-level tasks. When I took the 70-686 in beta it was so easy that it was silly.
It is unlikely that the training kit will have been updated to reflect a change in the exam. If you check the Microsoft Certification site and see the areas covered on the exam, as long as they haven't changed significantly AND the training kit covers those areas you should be OK.
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CompTIA A+, Network+, Server+, Security+
MCTS:Windows 7
MCSE:Security 2003
MCITP:Server Administrator
MCITP:Enterprise Administrator
MCITP:Virtualization Administrator 2008 R2
Certified Quest vWorkspace Administrator