I agree with the other post, that it would be a miracle for that "upgrade" to go well.
I generally don't believe in upgrades at all. When a new OS comes out, that's a great time to "clean the slate" and make a fresh new machine, with new versions of all your software.
That being said, at this point you might as well wait out FC5, since it'll be out in the next week or so. That will at least get you one version further in the same upgrade.
Tom