it's tricky. I would never run a verizon update on a modified phone (i.e. after installing multi-touch browser)... If all you did was apply the root patch, then you're fine, you can actually rerun the 2.0.1 update we got and it works perfectly as expected, and simply removes your privileges to run as root. But if you started making changes to your system, especially the locked system files that normally you can't touch, I'd be afraid to run any oem update as it could cause issues or it could just fail.
All that said, after rooting, most people then back up the entire state of their droid files (another process you must follow in my opinion when rooting). So thats what I did, rooted, backed up everything, then i started trying things. When the official update comes in, if the hackers haven't released a rooted version yet for me, I will most probably revert to my earliest backup and will be able to apply the official update. Only problem there is that then I will lose root
Anyways, if you're technically savvy or enjoy hacking into your phone, then root it up. But it's definitely not for everyone. rooting I think is built up to be some major change to your phone, but in reality it's as simple as installing one binary onto the filesystem. So there should be no fear in "rooting". It does involve some coding and if you like your droid the way it is, just stick with it in my opinion. I'm a software enginner by profession, and probably wouldn't hack my phone otherwise.