At this point in time, despite intentions to the otherwise, BTC is primarily a speculative cryptocommodity. As such, difficulty will follow price, with a lag. Not the other way around. That lag may be months behind the price, not days or weeks. I think the difficulty is just now catching up with the influx of miners that came around (including me) in the rise up through $10-15 BTCs. We're nowhere near the difficulty we'd hit with a sustained $30.
I'm not sure I understand this. We're not exactly talking about the chicken or the egg argument. BTC difficulty clearly preceded price since bitcoin exchanges didn't even exist during the first difficulty period. Difficulty came first, followed by price a ways down the road after it.
There was no speculative value then. Would you spend 10,000 bitcoins when they're almost worthless if you had any suspicion that'd be worth (at least in a bubble) over a quarter of a million dollars a year later?
Come on. Seriously.
A: Not every miner immediately rushes to sell every coin they get.
B: Even if they did, in 14 hours Gox had over 22,000 btc change hands. In that time only 4200 were mined (on average).
Imagine walking into a store that had 800 oranges for sale for $.20 each and shouting "Hey guys, I've got 200 fresh oranges here. They're getting harder and harder for me to grow, so I want a buck each."
Now imagine after buying those $.20 oranges, everyone went home, traded 'em for something else (or hung onto 'em a while) and came back to resell 'em and they were still perfectly good as new.
The only time you're gonna get to choose the price for your oranges is when the rest of the market is gone.