Appily will show ads in the final version (maybe even sooner to test various approaches). Frankly, I dislike inline ads like Pownce displays because mixing ads with messages from friends is just plain icky. Maybe others feel differently but I think the most boring approach, AIM, is the best way.
While the format is likely to be old-fashion, content will be very different. More on this later. I would like to talk to interested ad networks to discuss ways to integrate new types of ads.