Dual Thunderbolt displays with a Mac running Windows under Boot Camp? Is it possible, on a brand new MacBook Pro, to use two external Thunderbolt displays under Windows booted from Boot Camp?

I found this KB article, which says no. I also found this thread, where there's a hint that booting first to OS X then to Windows can work, but it's from late 2011. Have the drivers or firmware been updated to allow this more easily?
Unfortunately, as of now, you are unable to (I'm assuming that this is what you mean) daisy-chain two or more Thunderbolt displays (natively) into your Mac. I'm unsure if it's Apple to blame, Microsoft, or both. Wait until Windows PCs start receiving Thunderbolt (Microsoft should update the drivers by then) and try again. If that's not it, then it's probably Apple's fault and there is nothing that you can do now until Apple updates the Boot Camp drivers so that it can support this.