I'll break it right down for you my man.
It is clear to me, that you know the difference between root, and S-OFF. good. step 1, done.
so, if you were to not have S-OFF, so you'd have S-ON, and accept the OTA, you may NOT be able to get root back. This is unknown.
but
with the release of unrevoked new way to turn S-OFF back to S-ON, you can now run S-OFF(unrevoked forever) and accept the 2.2 OTA and keep root.
now, to answer your question of the correct steps I was speaking of.
make sure you have S-OFF, is step one, and probably the most important.
roll back to stock recovery, now, there is currently, two methods
1) rolling back from stock root,
2) rolling back from if you installed the leaked OTA which gave you the 2.05x radio I believe.
found here :
this website
follow the instructions for this, it is quite simple, you place the file on the root of SD and flash in HBOOT.
as long as you had S-OFF unrevoked forever installed, and you do this, you will be back to stock recovery thus being able to accept and install the 2.2 OTA, AND be able to re-root. thanks to S-OFF. and if you ever need a factory warranty replacement, you can run the S-ON. and still be good.
once you accept the 2.2 OTA, you will need to flash the clockworkmod recovery in HBOOT, to get that back. and then download superuser on the market.
hope this breaks it down for you straight.