Information Week puts it very nicely.
Here's what I think. Benefits:
- Connections to a zillion enterprises across the world
- Name recognition among end users, which Sun doesn't have
- It's entirely possible they'll be throwing some marketing dollars behind OpenOffice.org
But here's something else. People who hear of OpenOffice.org think "Why is it free?" "What's open source?" "What's up with this craaaaazy communist kind of software development?" My point is, there's nervousness surrounding something that's free and open source and not Controlled. (Anyone with experience with normal controlled software projects knows that's no guarantee of success, a good product, releasing on time, releasing at all, etc., but that's a separate issue.)
IBM has such a buttoned-down, conservative, reliable, "Nobody ever got fired for buying IBM" image that that might be the single biggest advantage about IBM's participation.
As the old Klingon saying goes, "Only Nixon could go to China." Perhaps only IBM could get OpenOffice.org on 51% of desktops.