Wow. That actually worked this time around!
To clarify, this is what I did.
1. Phone was already rooted, had my info on it, etc. I didn't delete anything or do a factory reset.
2. Launched the LG Mobile Support tool (make sure to install drivers first (it's in the support tool)
3. Now, because I had ran this before and it failed, it was giving me an error when I tried the update option because it thought my firmware was already up to date (v5) when the phone was still showing v3. Instead, I went to the Customer Support > Recovery Phone option. I entered in the serial and imei and clicked on check.
4. Before you run this, you'll need to put the usb debugging mode option on Ethernet. I had actually started this process while the phone was rebooting, it still worked to a point and then it said it lost connection to the phone (this was because the phone had booted back up and was in usb mass storage mode). I changed it to ethernet and click on restart and it continued the update process.
5. The program downloads the image file first, then reboots the phone and performs the update process.
6. My phone eventually booted back up - complete with all of my previous settings/programs. I checked the software version and it showed v5! However, it was still nagging me to install the update. I did so. Phone rebooted and performed the update successfully (it was failing in the past). Phone rebooted a few more times and then came back up UNrooted and with the OTA installed.
Now, in the past I've made different changes and thought things were fine, only to shut down the phone and it wouldn't come back up (bootloop, or some other error). As a test, I went ahead and pulled the battery and popped it back in. Phone started up just fine.
So, my advice is that for anyone who wants to unroot to either update or just wait for a solid ROM to be created, to try this method. If it fails the first time and then continues to tell you that the phone is already up to date, try what I did - rebooting the phone and starting the recovery/update process while the phone is booting.
If someone is willing, they can probably unroot, do a factory reset, then pull the fresh image for experimental purposes.
For anyone who's 'bricked' their phone, I would try running this program to see if it can maybe latch onto the phone long enough to initiate the upgrade process. The LG program seems to be able to resume the process if it loses connection, so maybe rebooting again and again will allow it to finally re-image the phone. Worth a try.
FOLLOW UP: For those that are curious, I was able to successfully re-root after this whole process. All of my existing apps that required root still work, and I was able to successfully re-flash CWM through ROM Manager, boot into CWM and run a backup. Also shut down and powered back on to ensure everything was working, and it was. No more ##@$@# OTA nag.