kde-4.9rc (kde-4.8.95) in f17 kde-unstable repo

[Neal Becker]

I'm thinking of trying the kde-unstable again.  I haven't done this for quite a 
while.  I'm a bit hesitant because IIRC following this path can lead to big 
problems to later get back into distro sync.

Is this true?  Is there a fairly painless way to:

1) Assuming kde4.9 goes into F17, get back in sync with F17?
2) Assume some disaster, go back to current F17?