I don't have anything in the App Store at the moment. And I wish Apple didn't take a 30% cut as I think it's still far too great - 15% would sit better with me. However, I'm excited at getting something in there because I know it's going to receive an order of magnitude (at least) more exposure than anything I've ever done myself outside the store. Sell-through also seems to be better as a percentage of viewership, at least according to some devs who have discussed stats.

Right now my sales all come via my web site - and some volume business via email. These visitors come with a roughly 33% split from Google, direct and referrals.

The Mac App store is going to expose my products to millions of people who would never otherwise stumble upon a link to my store/site.