So, where do we suspect they will most likely go?
Buying or selling?
When buying at Coinbase there's frequently the situation where they are out of stock, but you can usually always sell through them. So the 1% fee there plus there might be a little wider spread between the bid/ask versus Mt. Gox, but ether way, it's pretty competitive. The funds arrive via ACH direct deposit the same way that Dwolla withdrawals arrive.