well, i got the "old" one about 3 days before the new one was announced, but i wouldn't bother about the new one if you don't care about noise/looks. i got
this (will be opened tomorrow when exams are finished). now same price as the "new" one with no real difference at all, except maybe a few quid, but might be cheaper where you're getting it.
also, F.Y.I. the slim being "kinect compatible" doesn't mean the old one isn't, you just need a little adapter to "kinect" it, which is supplied with the thing anyway. hope this clears it up for you and thanks to Nathan_French_14 for saying about the warranty, i didn't know that