Yucca, exactly how familiar are you with MySQL? No stored procedures? Where have you been?
I agree that the roadmap for MySQL is uncertain at the moment. However, you have to keep in mind:
MySQL is GPL'ed. If Oracle do drive it into the ground, it will be forked (it already has been - see drizzle and others). Furthermore, why the rush to change Yucca? Current versions of MySQL are stable. Were you that unhappy with MySQL 5 (Yucca, apparently you have yet to discover stored procedures, views and triggers)? Unless you're an enterprise user and relied heavily on Sun for support, nothing has changed. The road from here on may be unclear, but give Oracle time to respond. MySQL's userbase is absolutely massive - it would be near impossible to bury the project and Oracle has shown no intentions of doing so. Don't forget Oracle provides Innodb - the only ACID compliant, and arguably most important, engine for MySQL - as well as BerkelyDB. I'm certainly not rushing off to anything else. Let's see what happens.
For all those starting new projects, looking for something new or parro'ing out like Yucca, I'd highly recommend Ingres. Fully featured, enterprise ready RDBMS and far more mature than MySQL. Awesome.