Its both actually. Or neither (and no I'm not being Zen). From where I stand I agree with Hari that leaving things as they are is fine especially since it has an added, albeit small, benefit of aligning nicely with other projects (HBase, Pig, etc all use 23 profile as a name). On the other hand if we want to pick the right name for this profile it should probably be disassociated from versions, since I would imaging both camps (hadoop 2.X and hadoop 0.23) using the same profile. So we should probably call it 'next' or 'ng' or something like that.
Just my 2c.