Yes, you can revert to the older grub. I would wait for at least two weeks
before upgrading. This way most of the bugs are worked out after a new release.

the comment on reverting to the older grub, but I was
actually wondering if there is some kind of way to revert back to the 9.1
OS... sort of like a system restore? I guess maybe I could ghost the drive
with dd or something, and then pull the ghost back over if the upgrade goes
awry... but I was hoping there might be some kind of built in way to back
out of the OS upgrade. Probably too much to hope for..

What I've done for many years is to install any new or experimental
configurations to a different partition and add it to the boot manager.
This way you can always go back to a configuration that works as you
migrate to the other one. As you resolve issues you'll use the old
one less and less. Then I leave the old one there as an emergency
or maintenance OS, which then becomes the space I use for the next
version/upgrade (presuming the previous one ended up working out).
Drives are large and cheap these days, there's no reason to restrict
yourself to one working OS on a machine.

The upgrade process wipes out the 9.10 installation unless you have lots of
hard drive space in which case you can have both 9.10 and 10.04. Just create
another partition and use grub to selection which one to boot.

In the installation process you should choose to format the root partition
because installing on top of the old installation can cause mega problems.
Even if you managed to do this successfully, your sources list would be for
lucid and not karmic and all of the old drivers and grub would be replaced.
I don't think that it would be a pretty picture.

The good news is that the new kernel includes more drivers and support for
devices. As for settings back them up to a usb stick and copy them back to
the new home folder.

It sound like installing 10.04 to a separate
partion would be best, but since I'm at 4 primary partitions right now, I
guess I will just stick with 9.1 since I really have no issues with it and
don't want the week of work trying to get fan, wireless, and such working
again.