According to
Bitcoin Watch, someone's on
bitcoinmarket bidding for 5000+ bitcoin @ $0.0639, which is much higher than the bid price at
mtgox ($0.0623).
If you've got bitcoins to sell, sell on BCM, buy them back on mtgox, and you've made a nearly risk-free profit.
cant get 5000 done at mtgox though at 0.0623, offer is .0624, but for 10 whole coins. Would have to pay .063 for the last 1000, if you get 5000 by then. But opportunity is there, you are right.
As a market maker, I'd rather buy 5000 naked at MtGox and then offer .0635.
edit: And with 25,000+ bid at 0.061 on MtGox, it would be nice to lean on that order. Buy buy buy!