Found some free Nokia developed Apps that don't show up in the Nokia section of the marketplace. Not sure if they are in beta or were intended for other markets/handsets but you can install them and use them.
Three of note are
TuneIn Radio - Internet Radio Streamer ... very nice! Keep in mind, will use data....
Tango Video Calls - It's like Skype, this version is optimized by Nokia though not sure if Lumia 900 optimized...
100th Day of School - Seseme Street educational game for kids
Finding them is easy.....
Go to the Market
Select the Nokia Collection
Click on one of the listed Nokia Apps
Click the "more from Nokia Corporation" link
