Actually I checked again and Google's announcement is correct,
the 2nd generation Nexus 7 is the highest pixel density tablet available: http://pixensity.com/list/tablet/
This now does not include phones/phablets etc.
I am going to pick one up on the 30th. Hopefully we can all chime in on a new-Nexus 7 review thread and see how nice this tablet is!
PS Anyone else have rumors/ideas of anything better in that form factor?