This is not good news, and Larijani has nothing to fear from Ahmadinejad. Good would be news hinting at a weakening, downfall or real change in Iran. This is merely the old Good Mullahm, Bad Mullah show. The novelty is just that today they take non-clerics. It's the same crap to fool the world (and Iran) with "Reformist" Khatami and "Conservative" Rafsanjani. Both sides of Iranian politics are pawns of the top Mullahs. Unless THEY are gone nothing changes.
Larijani is also a key figure in Iran's rise to nuclear power. His stance on Nukes and the US are no different.