yeah I felt really cheated by the ending, as did a lot of people. There were a bunch of reviewers that agreed too.

CL4P-TP is a ninja assassin and will be playable in the next game and the rest doesn't matter...

Developers didn't know what to put in the vault so they went with plan b and said sorry your shit outta luck come back in 200 years.

there actually is loot to pick up but if you sit through the credits, they all disappear.

lol

Yeah, I was kind of confused too until I realized that there is still more to the game after the credits. Heck, you even still have your final quest to turn in. Basically the entire game's story was paper thin and just an excuse to let you run around and shoot things. I'm quite happy that the Zombie Island of Dr. Ned seems to have a much stronger story than the entirety of the original game.

I just shot stuff and got mad loot.  Barely even payed attention to anything along the lines of a story.