Is that floating Posterous bar[1] on the bottom of the page new? Geocities used to do the exact same thing...
This, the GoDaddy bar in the admin panel that can't be made to go away and the spammer "subscriber" I can't delete even though he's not an admin definately have cheapened the experience. And the worst part is I can't even pay to make it go away like I could with wordpress.com.
It certainly turns me off Posterous -- quite strongly. I simply cannot stand stuff like that.