We previously reported that Microsoft would open up the Windows Marketplace for Mobile to submissions today, and Redmond's made good.  Registered developers can now submit their apps for evaluation.

And if that's not enough, there's a developer contest in the works called "The Race to Market Challenge." Devs will be judged on the most downloaded apps (free and paid), most useful (that'll be judged, and we'll definitely add our 2 cents) and most playful (again, judged, though we'd disqualify any fart apps on principle).

At stake are a number of prizes including four Microsoft Surface Tables, online marketing and promotion of the app, and bragging rights, natch. Of course, the competition can't begin until the Marketplace opens to consumers. And that will be ... well, Microsoft's not saying yet. Stay tuned.

Windows Mobile Team blog