The kernel does not require the new radio, but it causes much issues with ZVD-based ROMs. You should try it and let me know!
Also: whoever is going to write the rooting guide, you may use my ZVC (or ZVD) guides as a basic template. However the warning, info and note boxes will not work for you if you are not an Advisor, Mod, Developer, etc.
Note-I'm trying to port this to an Optimus V, do not try what I'm posting here!!!
OK, I decided to go ahead and risk my phone and try it out. I cleaned out the radio image and a few other things that made me nervous, edited the updater-script and build prop, added su, busybox, and superuser, resigned everthing. I did a nandroid backup of course, did a full wipe, installed the modified Sprint Gingerbread zip, flashed gapps, then flashed mmarz's sprint-to-ov zip file.
The phone started up, showed the standard LG logo, then all of a sudden there was an explosion and the sprint logo appeared, kinda cool actually. It then went through the standard android bootanimation, and next thing you know I'm at the account sign in screen.
I hadn't taken the necessary steps to get it working with the virgin mobile network, and the wifi modules don't seem compatible as is (at first), but I was able to boot into the OS, and use the phone minus network/phone capabilities. The interface is buttery smooth, and everything else seems to work great. Tried to power off and it just hung at the powering off box, pulled battery, rebooted, wifi works fine, signed into market fine. On second time I opened market, it upgraded. Email works fine, browser works fine.
Good news for future ROM upgrades and builds!