With the G1 officially launching today, so is the Android Market, where you'll be grabbing most of that open source app goodness. Their good news on the app front is that stuff will start pouring in on Monday when devs outside of the special Google-y few can start uploading their apps. And they'll all be free until next year. But that's also kind of bad.
No paid apps until next year means that the app selection is definitely going to be more limited. The real wave of games and other premium-level apps from established companies won't start until they can collect your $$$, so the pickings are definitely going to be slimmer than we'd like for the first couple months, which is kind of an issue with a phone whose power mostly rests with developers.
This isn't to say there won't be great free apps in the meantime. There will be. But we don't want to have to wait for the great paid ones, either. On the other hand, Google's terms for devs are fairly decent, so it should encourage development: Devs keep 70 percent, the other 30 percent goes to carriers and billing fees—Google isn't taking a cut. Hopefully these extra months will give them time to polish their apps and make them even awesomer. [Android Blog]