Frank Yu answered my call with a note on the state of next generation piracy in China (slightly edited):
Yes, the Xbox 360 hardware is totally broken for pirated games...however, if you leave your mod chip active MS will detect it and shut you out of Xbox Live. I have heard rumours of mod chips that can be switched off so that it toggle between a modded Xbox and an unmodded one to go on Live. I have brought many MS Xbox people to the shops here in China that do the modding (its not illegal to install the chip as far as I know but it is illegal to technically sell the console) (Editor's Note: Frank used to work for Microsoft in China). Folks at MS are always impressed by the speed and workaround that hackers and modders do to the motherboard. Of course we don' t tell them we're MS...there are a lot of foreigners who go to these shops too.