I believe that the current rise in price is extremely bad for bitcoin as a whole. I don't view it as a bubble at all. I see it as a wall.
The problem is that almost the entire BTC economy is based on BTC vs. USD (or other current currency).
Who cares how much a bitcoin is worth if sites are simply adjusting the price of their goods for sale in BTC to the current value of the dollar. It doesn't ever have to stop going up. It simply means that today a gallon of milk is .5BTC and tomorrow it could be .25. so if you go to buy .5BTC today it is 4USD if you go buy the BTC tomorrow it could be 8USD but the value of the milk hasn't changed. (Admittedly, I am not the best at putting my thoughts into sentences.)
The reason it is bad is that the seller of actual products, the ones who will help balance this whole thing out, that take the biggest risk right now because they have to pay for their product in USD... As the value of BTC increases, so does their risk in accepting it. For example, Biddingpond.com, how do I set a reserve price in BTC today for a product I want to sell. Today it may be fair. Tomorrow it could look ludicrous. Even worse, how do I bid on anything until the last minute? I know people snipe auctions anyway, but why list something for a week then. It would be crazy to bid until the last minute.
I am no economics guru.
Just posted this to see if I am missing something here or if my thinking is correct. Please educate me if I am wrong.