Yesterday Google announced that Android FroYo would include device tethering (the ability to use your handset to supply internet for a second device) and the ability to become a wireless hotspot. Unfortunately, TechCrunch is already giving us the bad news with it's report that individual carriers will likely have control over this ability when it gets released.
Hiroshi Lockheimer, Android's head of engineering, talked with a TechCrunch blogger and got an interesting response. Apparently, the data being accessed through the tethering isn't flagged in any specific way, but if a carrier wanted to, they could probably find a way to do that. Assuming they do, it is only realistic that carriers would "either charge extra for, or disable entirely, tethering on the phones they sell."
Androinica sums it up decently, saying that "Google is going to support it but the individual carrier does not have to. And if they do, they can consider it an added service, which may come with an added price."
As for how likely this scenario is, TechCrunch adds that we have seen both "carriers and OEMs have been molding Android to suit their needs for a while now." As for phones with stock Android OS, we have to wait and see.
Other Sources: Androinica
Image from TechCrunch