Last year the Las Vegas Bitcoin conference (Inside Bitcoins:
http://www.mediabistro.com/insidebitcoins/) was full-on MEGA with tons of people there. In fact, I think everyone was there. This year will be even bigger.
The conference in on October 6 - 7. You should book it up now. For all you Euros and Asians, Las Vegas is a great place to visit and will surely be the MAIN bitcoin event of the circuit. Consider a trip to Vegas.
While 'The D' hotel actually takes bitcoin, there are far nicer places to stay. The conference was at the MGM - not sure where it will be this year. But, the south end of the strip has tons of great places to stay.
See you all there!