The price/volume separation between mtgox and the other 'big' exchanges, BTC-E and Bitstamp, is at all-time high levels of around $500 total opportunity.
The graph I made/use to follow arbitrage potential is here:
https://cointhink.com/arbitrage/btcusdThe mtgox-btce difference I have always attributed to the difficulty of moving USD into BTC-E. The listed options on the BTC-E site do not inspire confidence at first look, or they do not exist. Bitinstant used to be popular for this but they stopped having available funds in BTC-E, then stopped all together (their website says they're rebuilding the service).
Bitstamp (and camp-bx) are also trading at BTC-E levels, which is a full 9% less than mtgox. I want to ask here if there are theories as to the source of this price gap.
Thanks,
Don @ CoinThink.com
ps. The 'total opportunity' is a calculation of the actual ask/bid skews between markets *including volume* to get a genuine total amount of opportunity of asks that are lower than bids.