Despite committee promises to "post news as soon as we have it" regarding hotel rates, the rates have been online, unannounced, for so long that you can find them using google. To save you a step,
The Lido Group is the official booking channel.
The A4 rates are shitful and the delay in annoucing them has cost most dearly. The Hilton's weekend pre-paid rate for bookings made in January
was $70/night below the con rate. Their pre-paid rate last week was almost $40 below the con rate, but is now only $20 below. The Crowne Plaza and Holiday Inn both have Entertainment Book rates (not even pre-paid!) below the con rates for most nights.
While looking at Lido's site, I thought I'd check rates at other conventions. The Fashion Exposed & Australian Shoe Fair Melb 2010, one week before Worldcon, is getting a rate at the Crowne Plaza that's $20/night less than ours. (The standard rates for both weekends are identical.) Bend over, fans.