It's been quite a while since we heard of T-Mobile and RIM teaming up for any announcements but it looks like something is cooking for March in Washington, D.C. Seems as though invitations were sent off for a special event that is welcoming those invited to get a look at what's next for BlackBerry. Hard to say at this point what it may be due to the lack of information available but hopefully we'll get some more details soon. Anyone care to toss some guesses around? The BlackBerry 7 logo makes us believe it'll be BlackBerry 7 related but that's not exactly a dead giveaway.