Lol, I finally dled this and watched it.
The hosts are actually Ogiyahagi, better known (well, maybe not..) as the hosts of Onegai Muscat, where they handle the circus that is the AV/Gravure collective, Ebisu Muscats. The part with Maeatsu was pretty funny and as always Mariko delivers with the air ocarina. I do wonder if she does really have interest in keiba though, it seems so weird to me. But maybe she's not geekily into it with stats and everything.