There are a lot of people complaining about centralization right now, but I doubt we'll run into the problem long term.
Here's why I doubt it'll be a problem:
http://bitcoincharts.com/charts/mtgoxUSD#rg60zczsg2011-05-01zeg2011-12-31ztgSzm1g10zm2g25zvAfter the big 2011 boom, we got to the point where everyone had video cards and the price was slowly dropping, along with the value of those video cards.
At this time large scale miners who had previously been hoarding GPUs began selling them off en masse, redistributing the hardware.
It's probably going to be worse for ASICs, because they have no other purpose than Bitcoin. If the mining companies can't turn a profit mining with them themselves, they're going to dump them on consumers as hard and fast as they can -- bumping the prices down for us. As in 2011, this will likely be a temporary state and Bitcoin will eventually begin to surge again.
I suspect the mining companies may turn out to be big long term losers in this game.