i'm not a google dev but it's confirmed that out of the box there is no 720p. Max resolution is 720x480.
However, the phone should support it since the Nexus one could and i'm pretty sure the galaxy s can as well. Hopefully within a few months (maybe weeks) of it being out with the source code people will be able to enable it.
Nexus 4 - AOKP Android 4.2.2 | Asus Google Nexus 7 - AOKP Android 4.2.2