I like the idea of being able to express very quickly that you like something, and I like the idea of putting a penny behind each like -- I think that makes the "like" more valuable. And I also like the idea of supporting the site through this!

However, I do not like the idea of these points/likes/kudos being redeemable for anything. I think the idea that a stranger was willing to toss a coin into your hat is already a beautiful thought.