I'm just looking for a way I can get Posterous great backend features working elegantly with Squarespace's solid UI features. Both companies pretty much entirely ignore the other aspect and if one or the other caved-in and took a stab at improving in the other area, I'd finally have just the right service.

Note to other blogging startups: If you can combine both of the above things well, you can have my $15-30/month, for what it's worth.

Edit: I'm going to try again and see if I can get them to talk through API layers that aren't exposed, but Squarespace didn't know of an easy way to do it-- ideally one service does it all.