What you're asking for sounds like a request for a new feature.
Let me explain what I mean. As I look at things, Kunena is not a community management product - and I think that view is on the public record by the Kunena developers and administrators - and so it lacks a many of the features that you'll find in products like JomSocial or Community Builder and others who compete in that marketplace.
I agree with you, though, that allowing people to enter their XBOX Live or Twitter profile would be a nice feature to have. Essentially, though, these details are no different to any other piece of information. There are no validation checks made by Kunena to ensure that (a) MSN or AOL or whatever is in a valid format or (b) that the information is "correct". So, basically, you could adapt any of those fields that already exist in Kunena to suit your purposes. All you need to do is to customise the PHP code, and replace the logo images, to reflect that you're reusing this data differently.
Would that not also work?
While, I'm sure, it's possible for the Kunena developers to add XBOX Live or Twitter to the list, they could also add Bebo, Facebook, MySpace, or any other social network into the mix ... and where does it stop? Now we're talking about changing the SQL table structure, and all Kunena users will have to convert their existing databases when they upgrade and ... unngghh! ... it will become an issue bigger than Ben Hur when everyone wants their favourite social network link represented! :laugh: