That didn't seem like a "geek" moment to me. Ledger's Joker is very overrated because of the hype because of his death. Batman Begins is what launched the realistic, reboot idea and gave fans the Batman they'd been waiting for since Schumacher took a **** on the franchise. Plus, every single person on the planet loved The Dark Knight, not just geeks.
On another note, there's a lot of geek chic in Judd Apatow movies, and Michael Cera and others have made it cooler to be a geek with movies like Superbad, Juno, etc.