I guess he wanted to end it while it was still fresh, which is a good thing, but I would love to see a sequel or another series focused on Hellsing/Iscariot/Mellenium.
I'd like to see an anthology of side-stories, that allows each major character to have their adventures without worrying about having it all tied together. Walter kicking ass in South America, Alucard working for Integra's father, Anderson destroying monsters somewhere, that sort of thing.
I've been out of the anime/manga scene for sometime, so I'm not too familiar with anything recent. My co-worker's promised to show me Black Lagoon this week which I'm looking forward to.