I'm one of the sceptics when it comes to the statistical losses that the industries purport to lose. I can actually see situations where piracy has lead to sales. And also I think the argument that many of those who pirate would never have bought the software anyway, so no real loss is made holds considerable weight There's a theft of easily replicated IP but with no real 'loss' due to this. Not that I am advocating for or defend against piracy.
I think it will be pirated as just about anything is these days on the web. I agree that at the price of Lion, there really is zero excuse to do so. I can imagine it to be more popular with Hackintosh owners however it's a popular practice I think now to buy legit copies of OS X for Hackintoshes nowadays, obviously in conjunction with the use of boot loaders and other software used to trick OS X into installing.