For what it's worth, Friedel started this same thread at lonelyplanet.com and it has lots of responses there too:
http://www.lonelyplanet.com/thorntre...40326&tstart=0
My list would look something like this:
UK end to end (next May)
Fall Colors in New England (next September?)
New Zealand
Southeast Asia
Icefields Parkway
Italy
More of France
Germany
Tasmania
Ray