Seriously, 8x4 channel bonded DOCSIS 3.0 will be out soonish, but that's at most 304/120...with one person spread across all eight channels.
So all Verizon has to do is push out a 350 Mbps down, 150 Mbps up tier and cable has to bring fiber all the way to the home to compete.
Heck, if Verizon came out with 150/30 right now cable couldn't compete, since even the highest-end deployments in teh US are one channel up, four channels down DOCSIS 3.
Can RFOG later be used as GPON? I keep trying to imagine what the limits are of a local MSO that uses RFOG with fiber drops. But when I see their aerials I think of everyone connected to a single fiber strand and something like fios, where everyone has their own individual piece of fiber back to those cabinets where they all connect to must have more future capacity? Then again I have no idea if those fiber aerials have a strand for each home, or just one large one for all?
Depending on how GPON is set up, it can be as fiber-dense as active optical or might just use one fiber per node, with splitters running off the main drag like coax. In answer to your GPON/RFoG question, I think they can actually coexist on the same strand.