Played around with one of these today at a Sony Store, and my initial impressions were positive. I really liked the wedge design myself, and didn't have any complaints about durability. I wouldn't recommend dropping it, but then again, I wouldn't recommend dropping any tablet.
The IR sensor will be nice as long as you aren't limited to Sony TVs and equipment. Make it programmable like a Harmony and it could be a very useful feature.
While some have mentioned that Sony (and all other Android tablet manufacturers) are behind the ball when it comes to tablets, I actually like the fact that there's variety. With the hardware pretty much the same in all tablets, it seems manufacturers are targeting different people with their tablet. The ASUS eeePad Transformer, Galaxy Tab, Toshiba Thrive, and now the Sony tablet has their own unique characteristics that give consumers choice. I personally like this approach.