I tend to think it is a more serious problem that only certain insiders are fully informed about.  Not to sling mud, but I would cease all dealings with Mt. Gox until the issue is made public.  Personally, I stopped dealing with them around the time of the CoinLab partnership announcement.  Whatever happened to that anyway...?

Finally, mtgox prices are higher for all currencies.  Just checked bitcoincharts.  Not a USD specific issue - it's a mtgox issue.  Not convinced the $2.9mm US Gov seizure is the end of the story, or itself enough to explain this spread.