Not the GP, but I was able to pick up a new 4gb model from the Acer online store a few weeks ago (the Canadian store - I don't think Acer is selling it new in the US anymore).
If you're unable to find one I believe the new Dell Chromebook 11 is fairly similar.
Marginally relevant - are ARM Chromebooks any good for development? I've been considering getting a Samsung Chromebook 2 when it comes out, but I'm concerned that important software won't be available for ARM.
Anyone running crouton on an ARM Chromebook care to comment?