Early adopters of Barnes & Noble's new Nook Simple Touch with GlowLight, are getting an unexpected surprise this week: we'd heard the device would be available in "early May," but the company let us know it's started shipping units early to some customers who pre-ordered the device. Thanks to "very strong pre-order demand," though, not everyone's getting their device early, and if you didn't pre-order you may have a bit of a wait on your hands. Pre-orders will be shipping over the course of the next month, and orders from today on are shipped as the company gets more availability. If you're itching for a light-up ebook reader, your best bet will likely be to go to a Barnes & Noble store, but apparently quantities are limited there as well. We liked what we saw from the new Nook, and if volume can keep up, it looks like Barnes & Noble may have a winner on its hands.