I agree with the fact that the ending was a bit disappointing.
I was really expecting something totally badass and amazing (though it was pretty awesome, in its own right).
What really disappointed me, though, was Light, in the end. Once he was discovered, he completely broke down and went pretty crazy. Albeit, that is what any normal human would do, but Light was definitely not just any normal human. I was expecting a lot more from him. Maybe managing to conjure up another plan in the midst of such chaos or at least remaining calm in his last moments.
On another note, my favorite part of the ending was when Matsuda shot Light. It was unexpected and completely awesome. I have newfound respect for Matsuda now.