Either they’ve accidentally announced it’s coming or this is one hell of a mistake!
From the Nook Fact Sheet [PDF link], this:
There is currently no B&N eReader for Android. This is what’s available at the B&N eReader download page:
No Android version! (No Windows Mobile, either — but who cares about that other than maybe Barnes & Noble?)
It’d be great to have a version that runs on the Archos 5 Internet Tablet and the leaked Dell Streak.