The new iPad is going to have almost identical specs to the iPad 2, just with a new display. Yes, it is a big, important feature, but it’s only one feature. Siri is a huge feature — the ability to literally speak with your phone — but it only earned the iPhone 4S status as an “evolutionary” product.
That’s a good point, but I think Apple is going to make a huge deal out of the Retina Display. I’d be surprised if the new iPad gains the “2S” title.