Cannot speak for linux as I don't use it, windows 7 is very flexable now over hardware changes, worst comes to worst you just run a sysprep and tick the generalise box, this way windows uses a set of generic drivers when you reinitialise it and not try to use the old motherboard drivers. (which was the big issue when changing motherboard in XP)
Not sure how well SSD's react to being partitioned for dual boot, main reason I use multiple drives is for safety, if one fails or gets corrupted the other should be uneffected and if unplugged then there's no chance of overwriting the wrong thing.
on windows 7 one thing I would say is to move the user profiles&floders off the ssd and onto the hard drive, yes this will increase boot times compared to running them off the ssd (as you're loading the profile and desktop) but windows is very messy over profiles and many bits of software dump tons of stuff into user data folders or just outright install themselves in there which means a user profile can grow rather large quite quickly esp if you dump files onto your desktop.