Dex I think there is alot you can develop, personally I would like to see something that could integrate with ebay and monitor auctions that you were in. Since the BlackBerry software is behind that for Pocket PC and Palm have a look at their top sellers and see if a corresponding item exists for BlackBerry.

Magpie, there are actually a few pieces of software on the market that will create email templates, we did a quick write up on Magic Mail that we like:
BlackBerry Edge » Blog Archive » Magic Mail Software a Must Have