This is probably the greatest win by a cyclist since Frédéric Guesdson won the 1997 Paris Roubaix on clinchers when Martin went onto win in the Worlds this September. I managed to get to talk to both Conti (UK) and HED (UK) about it. The word 'apparently' was used a lot as they were expecting him to use tubs for the event.
Apparently 1. HED.
Their wheels have been gaining a stealth like acceptance in the peloton, especially over the last two seasons. HTC, Sky and Katusha have all had great success on them, sometimes they are used in stealth mode with all stickers removed, other times the teams don't care. Tony Martin 'apprently' is a big fan of how the clincher wheels ride, offering more feel and comfort, so hence he opted to use these instead of the tubular option.
Apparently 2. Continental Tyres
I've heard this from various sources on their tyres in that the clincher versions have lower drag numbers (more aero is good) and much better rolling resistance than their hugely popular tubular tyres. They use some clever breakers in their tyres to try and avoid the dreaded puncture, which in a TT is probably game over if it had happened on the clincher. You can see from the photo that he has two different name stamps on the tyres, a 4000 RS and a GP Attack. After talking to Conti they weren't exactly sure what he was riding as they might have been hot stamps on new development models.
What we do know is that the clincher set up can provide a blistering fast set of wheels that allowed Tony 'Panzer Tank' Martin to blow the field apart. It's really a new dawn for clinchers and I wonder if we will see more Pro's use them and if we will see a big boy like Conti enter the tubeless market.