I may be being thick, but as far as I can see there are only two specs: with 3G and without.
I'll be having one as soon as its available (wifi will suit me fine, I think - I may go to the 32Gb, depending on final UK price), on the one hand : no real surprises bar the price (oh, and that you can use iWork - so a half decent laptop/netbook replacement), on the other: the price.
If the guys who do the CBZ reader's update to suit the iPad, then I'll be switching my 2000AD subscription to all digital, thank you very much (whether click wheel updates or not).
I fully expect the comixology guys to update their apps to suit - and, if so, there's a bunch of good, readable comic content already on there...
-pj