Oracle has uncharacteristically found itself maneuvered (by its own actions) into a rare hubristic place where it is:
This last point takes the cake. IBM, Microsoft and Sybase really don't want MySQL to take over the world, err, Web, any time soon, either. But they also want to coddle the developers who may begin with MySQL and then hand off to the IT operators who may be inclined to specify a commercial RDB - theirs - for the life of the app.
So it's a delicate dance to profess love for MySQL while setting the snare to eventually tie those new apps to the costly RDBs and associated Java middleware (and hardware, if you can). Let's not also forget the budding lust for all things appliance by certain larger vendors (Oracle included).
If Oracle, by its admission to the EU antitrust mandarins, thinks MySQL has little market value and is not a direct competitor to its heavy-duty Oracle RDB arsenal, than why doesn't it just drop MySQL by vowing to spin it out or sell it? Then the Sun deal would get the big rubber stamp.
It's because of what MySQL's worth may become. Oracle wants to prune the potential of MySQL while not seeming to do anything of the sort.