Bitcoin prices have been in a fairly steady decline since MtGOX went belly up.
For those that don't know, MtGOX was the main bitcoin exchange. MtGOX stands for Magic The Gathering Online Exchange; it started out as a place where Magic the Gathering players could buy/sell stuff.
Bitcoin's market is being undermined by similar product offerings out there - LiteCoin, Peercoin, Primecoin, Namecoin, etc. Besides, confidence in fiat currencies has returned for most out there.
There's an increasing supply and decreasing demand for bitcoin. I don't see any economic shock on the horizon that will cause bitcoin to spike in price again.