The next few months will be quite interesting. The reward halving is only one of the major changes coming. Given that there are three variables at work (reward, difficulty, value in fiat), it is quite difficult to have a clear sense of where things will end up. The introduction of ASICs and upgrades to bonds will further muddy the waters. We may only be able to determine if investors are behaving irrationally post hoc.
Yeah, I didn't want to muddy the water with difficulty stuff. Even if all the ASICs don't come out, there are increases in diffuculty coming from minirigs etc coming online, but the reward halving some something that known and I see so many times people say "the effect is priced in," but I don't see that happening here. I like GLBSE because there's some interesting data on investor behavior. I'm looking forward to examining the chart near the reward halving time (although ASICs may also be coming out then too, which will add noise).