It's interesting because I had the exact same initial reaction: uh-oh, did they change anything about my blog or group?

Personally, I almost never interact with posterous through the dashboard, but this move makes it seem that I'm either very much in the minority of their user base, or that they're no longer interested in serving my use case. Possibly both.

The net result is that where I would likely have used them without hesitation for another project I was planning on before these changes, now I feel like I need to look around and explore alternatives (including possibly reverting to a self-hosted WordPress blog).