I know Ed was responding kind of tongue-in-cheek, but I thought I would add on Jerry's response.
Based on my experience, culture is by FAR the more determinant factor to predict results of a corporate acquisition. Corporate culture very rarely, if ever, changes over the life of a company (of 4 companies that I have direct experience where they tried to change the "culture", all 4 failed to change it - that's 100% failure - but, of course, it was only 4 companies - yes, I'm generalizing <g>). Very small companies are the only ones that have a reasonable chance of culture-changeability, and IBM is not small.
So, the culture of IBM is definitely NOT in line with open source software (yeah, yeah, they've donated, blah blah, but their soul has already been sold <g>). How will that play out? Maybe something like Java. And that will probably mean new open source distros get branched off the latest Red Hat prior to IBM's purchase. Or maybe IBM will truly focus on charging only for support. But my guess is their bean-counters will not allow much time (cost) be spent on the OS if they are not going to charge just to buy it. And that means the IBM version of the OS will probably stagnate.
-Charlie
It could, but it seems unlikely that a culture as entrenched as the one at IBM will suddenly flip, for better or worse. I would imagine that mainframe salespeople will still be in their blue suits when pushing big iron to other corporate behemoths.
-Jerry