Why would Posterous sell to MySpace? They're hemorrhaging money, employees, and users, while Posterous is growing quite well. Selling to MySpace seems like it'd be a terrible idea..
Yeah Posterous might be growing, but they're still the also-ran of the social networks. Taking on the mantle of the former world leader would put them on a new level
Like when Dick Grayson became Batman for awhile. sorta
This is the equivalent of me saying "RIM should buy Apple. They have this cool new iPhone. I really like it. They should buy it."
Maybe, but that's not really how it works.
MySpace is pivoting, from a social network to a music platform for Indie artists. That's where MySpace is going. It isn't (and hasn't) tried to compete with Facebook for years (and I thought the MySpace/Facebook comparisons diesd a while back).
Adding Posterous and/or any microblogging to Myspace's current platform adds no strategic advantage to MySpaces' current service as it stands.
That said, Posterous is pretty awesome. I just don't see how it would be a useful addition to Myspace in anyway.