I was just over @ Microsofts dev forums, and noticed something odd. Apparently, the $99 / year development model will only cover paid app submissions. If you want to add free apps, it will cost you $19.99 per app. I can understand why they would do this, but it just seems silly. Especially if you look at the other major companies (Apple & Android marketplaces).
Read the forum post here (no login required):
http://social.msdn.microsoft.com/Forums/en-US/windowsphone7series/thread/bf5aa877-2ed2-43a1-8578-9e97cc044690
