Really it is my belief that Parthas last release IS the next official dev release Gimp-2.7.5.
It seems to me he has been one step ahead of each test release since he started compiling.
When he released Gimp-2.7.5 the devs released Gimp-2.7.4
I'm going to strongly disagree with you there. Partha is not compiling 2.7.5. He is compiling a snapshot of the state of the current development branch. Unfortunately the developers make the mistake (to my way of thinking) of labelling the current development with the version that it is targeted at. It only becomes that version when they freeze the code.
So they froze 2.7.4 -which can then safely be called 2.7.4 because it never will never change.
Personally I think Partha should stop calling it 2.7.5 and refer to it by some reference to when he grabbed the latest code and compiled it: i.e Gimp-latest-03-02-2012-11:59:03