Well, I've never tried a Kindle (never even seen one, actually), but if you want my opinion I'll willingly give it. So, for something like this there are always going to be pros and cons.
The pros, of course, is that it's compact, light, and saves a lot of space. Watching my closet slowly overflow with books makes the Kindle look great, actually. Plus, you can get new books a lot cheeper than in print. $10 for a NYT bestseller is way better than $26 for a hardback.
But, the Kindle itself is freakin' expensive. So it couls take a long time for it to actually be worth the cost. What would bother me the most would be recharging it. Sure, the battery power can last a while, but who hasn't had their, say, cell die on them because they forgot to plugg it in? And the other thing is that a lot of more obscure or older books you couldn't get on it.
So anyway, I thinks it a pretty cool little machine, wouldn't mind having one myself, but I think it'll still have some setbacks compared to your good ol' fashion paperbound.