My guess is that it is a hoax.
A reverse WHOIS lookup of the johnmccain.com and johnmccainvp.com are not hosted in the same place. Although ownership of both sites was by proxy, it seems unlikely that this is a McCain site.
While just typing random URLs into the bar, I found http://www.mccainpalin08.com and http://www.mccainfiorina08.com , which are both parked at Godaddy. They trace through Internic Whois to Godaddy as well... just for fun, I suppose.
www.mccainpalin08.com was created in Feb. 2008 - rather insightful, don’t you think? However, www.mccainfiorina08.com doesn’t yet show up on Internic Whois...
Those are the only two I have found so far!