A picture taken apparently during the setup of WWDC has begun circulating around the mac web. Much of what the banner depicts is nothing new, however some have pointed out that Apple is once again touting 64-bit application development, and the desktop model depicted looks very similar to today's PowerMac G5.
Core Duo (Yonah), currently used in today's iMac, MacBook, MacBook Pro, and Mac Mini computers, is a 32 bit processor whereas Core 2 Duo (Conroe/Merom) and Xeon are 64 bit. A recent page 2 rumor indicated that in addition to a Mac Pro introduction, the MacBook Pro may be updated to include Merom which would leave only Apple's consumer systems with 32 bit processors.
Also of note is that most of Apple's most sensitive banners at events are typically heavily guarded and draped with black cloths until the related announcements are made.