According to those lucky enough to have a Nook, firmware 1.1 is live now. Forums are full of sporadic claims like faster page turns and tweaked file handling.
Because in the words of our own Wilson Rothman: "It feels like not much has changed." The only thing he notices off the bat is that returning to the book you're reading, after going to the main menu, is quicker, though it's still just as slow to load a new book up. As for page turns, he's still seeing the 1-2 second page turns he saw before, and the highlights-and-notes bug he uncovered during his review seems to be unrepaired.
It seems the Nook - a beautiful piece of hardware in its own right - is still in need of one heck of a firmware update. [Teleread Thanks JP!]