I think it took a couple of weeks (maybe it just seemed like that) for them to actually figure out how to re-root the update. It wasn't until they found the security hole in the flash lite plugin that they were able to regain root access. They couldn't even flash old ROMs and root those because the bootloader was locked down. I imagine everything is going to be even more locked down than last time. If you want to keep root access at all, I wouldn't update until the hackers get a chance to dive into it. Then again, if you can live without root access, by all means, update since Froyo looks awesome.