[H3g3m0n]

That one probably took a lot longer as it was a complete rewrite to deal with the core profile. 4.3->4.4 would only have to add the 4.4 stuff in.

4.4 doesn't seem to be a major change. Only adding some buffer stuff, DX10 compatibility and mega-texturing.

[zero_one]

They probably wont put out another edition just for 4.4. They didn't for 3.3 and after all the complaints the 7th edition received, I doubt they'll put out another insignificant update.