The one and only reason to buy a PSP Slim is the TV out function!
that and the weight, the better screen, the UMD caching / faster loading, the new TV reciever, and the oodles of other things i am worried Sony might do to actually make the PSP-2000 model appealing.
anyway, if all you want is TV out, you might as well buy an ipod video - you'll get 60 gigs of storage that way, rather than spending money on over-priced memory cards, and at a much cheaper cost than the new PSP.... and you can get the cable for under a fiver.