We've been informed today that there are going to be no more Backward Compatibility updates released for the Xbox 360 until March at the earliest. Microsoft's David Reid has stated that the team who do the BC work are on holiday throughout January and will start work on priority titles when they return. But from what it sounds like, there will be only a few more updates released through 2006.
This will come as a disappointment to many new Xbox 360 users, not only because the lack of new 360 titles but also any new plain Xbox titles they may like the look of (Black for example) will not work on their shiny new 360. It is no wonder less Xbox games are being sold now.