Croesus
Adventurer
As for third party tools competing with DDI stuff, I don't think this would be too big a problem.
Your comment got me thinking: how much 3PP crunch would people buy and use if it's not easy to integrate into a 5E DDI?
I don't believe we yet have any hard info on what 5E DDI will look like, but I'm assuming WOTC will have something up and running when the books are released. If so, and if (big if) a lot of 5E players subscribe, that could be a factor in limiting what 3PP material is bought. Adventures wouldn't be a problem, but new classes, themes, feats, etc. might be. WOTC could offer a somewhat open OGL, yet try to limit it's usefulness by making it difficult to use non-WOTC material in a 5E DDI. I would hate that - I houserule a lot - but I could see some in WOTC management thinking its a great idea.
My preference is for the "app store" model that Pinback, Delericho and others have suggested, but I'm not sure WOTC can or will implement anything like that.