Actually Crazy Taxi got shield support about a week ago. I didn't post the information, as I figured anyone with a Shield would have known, and I just didn't think interest would have been that high. I haven't played it in years, but it was a very good game when it was released. I don't know how well it has held up, but I may give it a go.
In regards to some of the comments that the Shield isn't really portable, personally I haven't found anything to be really portable since the DS lite and the WIZ. I think the Pandora is way to big, but I find everything else to be big as well. Of course the Shield is the biggest of the bunch, but I don't think most of the devices in question are all that small either.
I'm a backpack guy, so if I'm going to an appointment or some form of travel, I've got a backpack or some form of luggage, so any of the current devices fit me well in regards to size. As long as it's fits my bag, or the passenger seat of my car, I'm good to go.
I love the Pandora's form factor, but I've never thought of it as portable. I remember some of the early reviews, showing it along side the devices of the time, and it was HUGE. I've never personally change that picture in my mind. So while I'm sure the Shield is BIG, that won't bother me at all. Now the weight, that's a different matter
Chris