It seems as though numerous "hints" have been dropped as to the possibility of running Managed Apps on the XBox 360. Some of the latest news is that Tom Miller has actually moved over to the XNA and XBox team. On top of that, there was this latest post from David Weller. One of the quotes:
Speaking of XNA....we have some wicked cool stuff to announce and demonstrate at the GDC. We even have a prototype of a CLR-based graphics app running on a 360 dev kit! Drool-tastic :P
Now that's interesting! How much more information do we need before we can start "putting together the puzzle pieces" in order to form the full picture?
Feel free to "rumour-mill" away :).