I'm wondering why there aren't any plugins regarding this. I'd like to trigger some Battery samples using a drum pad and I would like to do it though a plugin. I see however that it may not be possible. I used to have a Drum Hardware Module (Alesis DM5) but I have since sold it. Maybe I shouldn't have :O Is that the only viable solution??

Check out that midi guitar thread. It may do what you want.

Also take a look at the Fishman Tripple Play (when it's released):

http://www.youtube.com/watch?v=5UZ7Qv5H_2k