Not entirely -- I mean, yeah, they are completely replacing the kernel, but it's still just files on a hard drive. It should be extremely tricky to try to continue to run in the transition state, but once you're in the new operating system, if it's working, then it should be working. Try exercising various external devices (I.E. as many different drivers) as you can -- if everything is still honky dory, then everything is probably honky dory.