Apparently the Kindle is a great success, financially, for Amazon. That's good to hear, though I haven't made the decision yet. I've been looking for places/times when it would help me, but I haven't found a ton.
And I think I might suffer from the same issues that my friend, Ted Pin, suffered from. I'd buy too many books. When I asked Ted about his, or his wife's, they were going to return it. But not because they didn't like it. Rather because they were spending too much $$ on books. I could definitely see that happening with me, so I'd need some budget as well.
I still like the idea of carrying around lots of books. I've been stuck a few times with no books handy, and a Kindle would be nice, but I'd have to carry it everywhere to be sure that wouldn't still be the problem. With 3 cars, I'm not sure that I'm not better off just stashing 2-3 books in every car.
I've gotten up to about $200 in my Amazon account, so I'm getting close to just trying it. I'm thinking perhaps to wait another month and see if there are any new announcements coming on changes or a new version. My guess is it's slated for 2009 to get through another Christmas season, but with competition from other areas, perhaps even Apple heating up, I could be wrong. If I were Amazon I'd be getting a second version out, lower the price, and grab market share. Once people have one of these, they're unlikely to switch to something else.