Kinect is great if you have a large enough room to use it in. Still a little delayed, but the improvements will come next year (and I'm guessing they will be software based, since the device runs at 1/4 of the it's capable resolution at the moment). Improving that should improve accuracy and allow up to 4 people to play at a time (again, you'll need the space!).
Other than that, the fall update is supposedly going to replace certain set-top boxes that cable companies offer and you'll be able to watch cable TV through the XBOX. That is, if MS comes to some agreement with the network(s).
That will make it THE home entertainment console to own.