Skype is buying GroupMe for a reported $85 million dollars. While a lot of conjecture exists around the why, I think that the former Startup Camp participant's value was in the fact that they really do handle SMS for groups and with Skype heading into a small group/small business mine field where the mobile handset becomes a core "reach" location it was a piece they were lacking. That and some deep understanding of Windows 7 Mobile, which GroupMe has. I mean, Skype on Windows Mobile hasn't really been a focus for many years and with their new masters being the Microsoft folks, having development insight brings a team in that kick starts that from the outset.
The second reason is to be more competitive with Google. GoogleVocie has a very robust 1 to 1 text messaging platform based on Syniverse platform. But it's very much a person to person messaging solution, just like regular SMS. My guess is Syniverse comes out with a group solution very quickly to give the carriers a defensive posturing tool against Skype.
Third--Skype's SMS was limiting. It was one way mostly. Unreliable and not very well developed. It was really an add-on and not a core part of where the company was headed. Group Me solves that problem for them.