Okay, it is 8 hours on the 17", my bad. Still, I haven't seen anyone getting anywhere near the official number around work. I believe 3 or 3.5 on an Air, but 7 on a 17" MBP must mean *very* light usage (cf.)

Anyway, when I said "couple of hours" I was talking about my current MBP, not the new models. I'm sure the new 15" unibody can get through 3 or 4 hours of typical usage, and that's great, but that doesn't mean having swappable batteries wouldn't help a lot of folks out. It just isn't the "typical" use case, and Apple is legendary for over-optimizing for the typical use case (see also glossy screens, the on-again off-again love affair with Firewire, ExpressCard, etc.)