An article at Reuters describes the cloud of secrecy that continues to enshroud the device, even among its primary sales team. In interviews with anonymous employees (they're barred from speaking with the media), Reuters notes that none of them have seen an iPad, including store managers and Geniuses. "We haven't seen it; we never do," said one employee. Additionally, the Apple Store Geniuses haven't yet been briefed on how to repair iPads.
The iPhone's launch in June of 2007 was monitored just as closely by Apple. In fact, Reuters reports that one Apple Store saw two pallets of iPhones arrive 24 hours before launch day; one contained boxed iPhones while the other was just a decoy. Additionally, an assistant manager was told to remain in his store overnight, to provide added security for the iPhone prior to launch.
The moral of the story is, don't bother poking around the store and pestering the bright-shirted workers. There's nothing they can tell you.