Historically, any modern game released on all three platforms will sell more on the console's than PC. It's very, very safe to assume that Skyrim sold more on PS3 and 360.
However, I'm sure that the percentage of PC purchases to console is better for the Elder Scrolls game than, say, Call of Duty.
It's an ugly and vicious cycle though.
If the game developers/gaming industry hadn't turned it's back on PC gamers in the first place, maybe consoles wouldn't have taken off as much as they have. After all, as a game developer, if you want to take a risk in making a game you do it on consoles, that's where most of the innovation and new ideas have been going for years now.
The only excuse game developers give for turning their back? PC game piracy. Except at the GDC, it was proven that PC games piracy has long been on the decline while games developers still cry about it. On the flip side, no games developer will cry about console piracy even though Crysis 2 and Skyrim both had cracked/leaked console versions before release day and before there were cracked PC versions.
So where's the love?
If you're going to release buggy, untested, rehashed, garbage to PC gamers and then cry about PC gaming piracy don't blame the PC gamers and consumers that your game sales figures were low. It wasn't their fault.
It's like the recording industry blaming grandma and suing her for $750,000 saying it's her fault that people don't buy CDs and not because they keep releasing albums with 1 good song and 19 garbage ones but increasing the prices.