I don't think that bandwidth should make a difference to the argument. In fact, the proliferation of SSDs could be an argument for sticking with 32 for a bit longer, due to the (often slightly) smaller file sizes. Only thing that really matters is the amount of RAM dealt with.
Still, if the next version of windows is 64-bit only, that'll reduce devs' mentality that they have to produce a 32-bit version, and thus can't be bothered/don't want to confuse customers making a 64-bit one.