OtterBox had a hell of a time scaling their case design practices up to something the size of the iPad. I have to hand it to them, though, they've done pretty well for a first attempt.
They are, however, not nearly as good as the iPhone/N900/N97 mini/Bold 9700 Commuter/Defender cases that I've tried and tested. I think there are some difficulties associated with covering something as big as the iPad that they'll need to resolve with new techniques- particularly the way the rubber on the defender version attaches to the underlying plastic case, it's really difficult to get right.
The Commuter case had me stumped for about half an hour, I just couldn't figure out how to get it on. But once on, I really liked it. It's a damned good example of a silicone/rubber case and actually looks pretty good.
The defender was much easier to get on, but the rubber layer is a nuisance to get seated correctly around the plastic frame. I loathe to say it for fear of belittling the sheer amount of effort that has gone into producing these cases, but I'm pretty sure OtterBox can do better! The Defender also has a gap around the slide-off dock cover and, on my sample at least, a slight gap above the Apple logo portal, both of which show the silver back of the iPad.. if only slightly.
The Defender also doesn't afford the iPad any screen protection (apart from with the supplied screen protector) which is a bit off. Those of you who have used an iPhone defender case will appreciate why, though. OtterBox had an issue with the thick plastic screen protector built into those cases, where it would "suck" down onto the iPhone screen. This could be more or less solved by also applying a screen protector, but imagine scaling that problem up to iPad proportions!
Fortunately you can clip the big plastic shell (which doubles as a stand) over the front to protect the screen in transit. But that's not going to help if you're placing the iPad in the hands of small children. That said, my 3 year old hasn't dropped or abused mine yet.
To summarize: the Commuter is a great case with brilliant edge protection but was, for me, a nightmare to get onto the iPad. The Defender is, as is typical of OtterBox, absolutely rock solid in terms of edge and corner protection- no other case I've tested comes close - but is somewhat lacking in screen protection.
I wouldn't hold your breath for a version 2.0, these were a long time in the making.