Yeah, I wouldn't trust the TPM - certainly not from a Windows machine, and not even an Apple one after the recent revelations/research, which shows Apple tries to make the device secure against "regular" hackers, but very easy to access by Apple itself or the US government.
My current one is from atmel in 2008, before atmel quit making them, so I figure at least in this case I'm safe. I would probably not use a newer one if I was worried about TLAs though. As I am currently in the market for an MBP, where do I find this information about Apple TPMs?