I have to say, splitting things up makes me think of the whole Netflix-Qwikster thing - pointless brand splitting that does little more than confuse and frustrate consumers.
The intention was to branch off Qwikster and have it slowly die. I actually think it wasn't an awful idea, but that they did it too early. With a terrible name.
I suspect Foursquare want to slowly kill off checkins in a similar way.
I do like the new logo though.