Yes, I think it's pretty clear it's 2011 because the girls are featured in other photos we've uncovered. Maybe the guy just added them to his 2010 set because he was too lazy to create a new set?

My thoughts are that although FB is helping to spread the awareness of these events, probably not too many pics are being posted there instead of flickr b/c flickr is still more anonymous. I know I don't want my family & friends seeing the nude pics I'm snapping. Flickr is probably losing posts b/c people know there're pervs like us posting 'em here. Hell, lately I've been posting here before flickr.

Yet the number of B2B photos on flickr is shrinking annually...

I agree that shooters won't post potentially pervy galleries on their FB, but that wasn't my point. B2B isn't a "nude event." It's a huge cultural event that happens to involve some very limited nudity. Most of the photos we've found on flickr weren't from users who specialized in naked subjects. They were a small subset of much larger galleries depicting the entire event in it's entirety. Most of our naked pics came from photographers just documenting the event, with a naked photo or two sprinkled in.

If you shoot a gallery of a naked event, you wouldn't post it on FB. But if you shot 500 photos of B2B and a handful of them contained nudity, you might post them on FB and post a couple "LOL! Crazy naked people!" comments to innoculate yourself from the assumption you were a perv.

And let's be clear about what we mean by photographer, in the case of B2B. Usually it means a participant, a party-goer. Most of the pics I found on flickr were taken by people participating in the event, most likely with a drink in one hand and a camera in the other. Again, these kind of party pics are what FB specializes in.

Conversely, I don't expect WNBR or Fremont pics to shift to FB. You're right about the perv factor. No one wants to own up on FB to the fact that they deliberately went out and set about to shooting naked people. But I think B2B, where the nude shots can be declared "accidental," this is a factor.

Two Topless Girls
 

Yes, the turnout of topless or nude women was very low. Part of the problem was a weather prediction of rain and hail. There was a shower or two, but the weather was pretty good, by San Francisco standards. As usual, there were 10 to 15 nude males for every nude or topless females. Here are a couple of topless women near the Mile 6 marker, where "official" photos are taken.

Bay to Breakers 2011
 

I agree with nakedhippie about Flickr still being the most popular place for these event photos. Not only is Flickr more anonymous, it's also geared towards photography. As flanker7 also mentioned, I think one of the reasons the nude turnout seemed low is because the race organizers cracked down on allowing unregistered runners without a bib number and a shoe chip, known as "bandits," on the course. This probably cut down on unregistered nude runners, and kept unregistered photographers from walking the course among the runners.

There good HD videos of the race, taken from a fixed location, by a couple of YouTube users.
-65seasons
-kevinsyoza

In addition, you can find some good photos of nude runners from the official race photographer, SportPhoto (sportphoto.com/). Look for the following bib numbers:
Note: Photos from Sportphoto are watermarked.
2786 & 2787
9624 & 9625
15751
26860 & 26861
42271 & 42272

If you go to the official website (zazzlebaytobreakers.com/), click on "live results," and enter the bib number, you can see a video of the runner crossing the finish line.

Also 37767 & 37768
I recognize her as Li'l Phi (Li'l φhi) from Voyeurweb. She mentioned in a photo contribution that she would be at the Bay to Breakers. See more of her here:
damiensdomain.com/EIP/lilphi.html

Still not much, but here are a few. I threw in a few NN because these girls are hot.

This girl is probably the most photographed of B2B. She's obviously employed some double-stick tape, as I've yet to see a slip in any of the photos. Still, given that her friends are completely covered, it's a pretty daring outfit. The last photo is about as revealing as it gets. The lei has moved aside so that just the tape covers her nipples.

Actually, based on the way I uploaded them, it's the 3rd photo and not the last where you can see the tape covering her nipples...

Beautiful
 

Those are technically and subject-wise brilliant pics. Thx.

Steve Nguyen's
 

hxxp://vader.smugmug.com/Other/Bay-to-Breakers-2011-Bare/17511041_6wsnFQ#1332754135_QspJ3qG

Steve Nguyen's NSFW B2B 2011 page is now up!