During the demo, you could clearly see GarageBand, iMovie and iPhoto icons among the available apps. Indeed, the screenshot on the official Lion information page shows the same thing. It's impossible to see what the cost will be (we *think* it says $14.95), but the idea is interesting. Many users buy the bundle for one or two apps only (iMove and iPhoto, but not GarageBand for instance). An a la carte offering would prevent those shoppers from paying for an app(s) that they won't use.
The Mac App Store will premiere for Snow Leopard users in about 90 days. We'll know for sure by then.