You couldn't have it more wrong, this time. As I understand it, Mitch is not attempting to create an Outlook killer, nor did he claim to be doing so. (Slashdot dubbed it an Outlook killer, not Mitch.) He is attempting to create an alternative, yes, but to paraphrase Steve Jobs: Outlook does not have to fail for Chandler to succeed.
I worked on Lotus Agenda's first couple of releases (after working on Lotus Metro, which preceded it as a PIM offering), and I have always been frustrated by Outlook and most of the rest of the genre (including, by the way, Lotus Organizer). All are entirely too inflexible, in my opinion, to manage my information in the various forms it takes, or to present all of the relevant information I'd like to see right now.
Agenda was conspicuously good at this flexibility. It suffered from other constraints of its time: the limited bandwidth of a character-based interface, the lack of standards for representation of information, and the immaturity of networking and e-mail. Reviving its concepts in a modern environment could be exciting and empowering.
Outlook's current success represents the calcification of the software industry. Very few personal computing applications are substantially better than they were five or 10 years ago. This is largely because the purchasing decisions are now made by IT organizations, usually for their administrative convenience and sometimes at the expense of the user's needs.
If Mitch is taking even a small part of the software industry back to a model where features are decided based on user benefit as opposed to IT checklists, then the entire industry stands to gain by the infusion of fresh ideas. It is interesting (and regrettable) that he finds it necessary to pursue this outside the for-profit software arena.