Having just moved, I find myself restricted to a 3G connection until Broadband gets set up here. However, this does allow me to give some feedback on using the online stuff over such a connection.
I’ve got to say, it works far better than I had expected it would. The transmissions are clearly very lightweight, and I’ve not run into any problems, even with playing online challenges. Even downloading the patch (1.003) wasn’t painful. As such, this isn’t something that needs fixing; I just figured it was worth noting, and let you know my experience with it.