x264 is a codec implementation, not a codec standard. The x264 source code is free, but what it produces isn't (at least in the US). Rumors are VP8 will be free on both counts.
As for the patent issue, Google has no doubt done this during its ~9 months of due diligence while buying On2. Not saying that issues won't come up, but Google apparently felt comfortable with the situation.
As for the patent issue, Google has no doubt done this during its ~9 months of due diligence while buying On2. Not saying that issues won't come up, but Google apparently felt comfortable with the situation.