Much of it came from folks citing a Cringely report that IBM was about to lay-off 150,000 developers. The final number was 1% of that. Their total software headcount may be higher than it was in mid-May, owing to other acquisitions.
It's true that IBM's software strategy is changing. It's looking to sell more software, often built into hardware, than services based on its writing of server code.
But would RedHat be defying Microsoft's patent claims so strongly if IBM didn't have its back? The head of the Open Invention Network is a former IBM executive, Jerry Rosenthal, and the strength of OIN's patent portfolio is tied closely to IBM's contributions.
Just because IBM is not pounding the table, or betting its entire future on Linux, does not mean it's not the key to open source's future. Without IBM's support and contributions, I don't think Linux would be in such good shape.