As everyone is expressing their opinions and making predictions today, I'll do the same.

I was very surprised when I heard the news.

I think it's quite likely that an independent commercial entity working on MySQL will arise outside the merged company and that many of those on the inside will defect. This would be great because it would prove decisively that you can't kill off an open source project by buying the company that develops it.

I think the deal is far less good in general for Linux and Open Source than a takeover of Sun by IBM would have been. In particular if IBM had bought Sun, I think it's fairly clear that opensolaris would have been relicenced under the GPL. In the case of Oracle it's less likely, though it's possible they might contribute ZFS to the Linux kernel (after all they have been working on Btrfs as a competitor to it).

I'm not sure what it means for OpenOffice.org, but maybe there's a possibility that Oracle will put resources into it purely out of a wish to do Microsoft down.