I'm usually an advocate of doing clean OS installs when upgrading (doing a full backup, wiping the drive, then installing the new OS from scratch, then doing fresh app installs, and populating data from backups). It's a long process, but something that seems more reliable and less clunky from my experience.
As usual, proceed with caution before doing an OS update like this. Aside from apps, you'll want to be sure your various audio/midi drivers are playing nice.
If you decide to take the plunge (aka: volunteer as the guinea pig :), please let us know how things work out for you.