Many will disagree, but the way I see it they're fire and water. Commercial developers HATE to see quality OSS applications appear as they bite into their income, and the only way to battle that is to develop more complex/powerful/polished (and thus costly) software.
This is aggravated by NIT users not as accustomed to paying for software than any other platform's users.
Add to this the problem of DRM lack, which will further lower your income
As for the flip side, if you make a push for commercial apps, any change you introduce to make commercial apps more competitive will undermine your OSS potential. OSS projects build the community from the savvy userbase, so if your userbase is driven to or naturally becomes a commercial app user, the OSS projects will wither (if you have a super-snazzy super-powerful super-supported super-quality app for 1$, who's going to manage to draw enough attention and community to build a quality alternative ?). In this scenario OSS projects whither to hobby projects, carrying little value to the end-users.