EVER is a long time.

If the miners sell all their coins, probably to cover their expenses and recover their investment, the exchange rate will be exactly at the level where the coins sold equal the fiat converted in bitcoin.

3600 BTCs/day at 360$/BTC is 1,296,000 $ converted every day in BTC.

If the quantity of $ in the economy increase faster than the quantity of BTC, the exchange rate will increase. But the $ inflated and is inflating less than the BTC, so the exchange rate fell for all of the last year.
What keep up the price is the usefulness of BTC in specific applications. And this usefulness drive adoption. In the last year the usefulness of BTC increased a lot. At this level, apparently, the usefulness of BTC compared to fiat money and other payment systems is able to drive enough adoption to drive the price up enough to compensate for the greater inflation.

By july 2016 BTC's inflation will halve around 4,5%. before of this, probably in the 1st half of 2015 the Federal Reserve will start some type of QE again. If they don't, the interest rates will soar and the interest rate paid by the government on new bonds will explode destroying the budget. The government will be forced to pay more than half than their revenues in interests or default. Compare the 2% paid today with the 20% paid by Paul Volcker's Fed. So, they will be forced to print, before or later. Before in more probable than later. If the government don't pay it's bonds, a lot of banks will default (because a lot of their money is in government bond), a lot of people and business will default (because near all of their money is in their bank accounts) and a lot of business will default because people will have no money to spend.