Pirate has the BTC, the price movement depends largely on what HE does - buying Ferraris = down, holding BTC for a nice retirement = stability/up.

There may be some up movement to BTC if people panic on GLBSE and sell other stocks/bonds and move back into BTC.

Based on how little the Bitcoinica hack did to price I am guessing the effect of Pirate either way will be small.