In this interview with Gamasutra Microsoft's Aaron Greenberg addresses some possible worries about the new keyboard controller attachment and windows live Messenger dashboard integration:

What can you tell us about the add-on peripheral mini-keyboard controller? It looks interesting, but also looks like added weight could be a concern.

It is actually very light and fits perfectly with the controller. I was playing around with it today and you can hardly notice that it is there. It is designed in a way to still have a comfortable feel so that your gameplay should not be affected. Of course, being able to quickly snap it on and off, similar to the headset, allows our consumers flexibility if they don't want it always connected to their controller.

Are you worried about Messenger spam? It seems like that would be particularly annoying if it popped up while watching a movie, for instance.

We are not worried about Messenger spam. Privacy settings on the Xbox 360 allow you to choose if you want to receive messages from all gamers, friends or nobody. You can also appear away or offline to people on your friends list so that they won't send you messages when you don't want to be disturbed.

We have also built in the flexibility to, for example, appear online to your gaming friends but offline to your IM friends. We want to ensure that our consumers only receive messages when they want them.

I like the new keyboard attachment (finally, a painless way to name your Viva Pinatas) but the only feature I really want the Live Messenger to have is the ability to turn it off -- all my friends are on AIM.