[tokuzumi]

I used that guide (the one I used was on XDA...) to an Evo that was having issues. It was rooted via Revolutionary, and when I was done unrooting, it showed the correct hboot (for the GB update, since I wasn't interested in going back to Froyo), and showed S-ON. No evidence my phone had ever been rooted. Your hboot might show the version for the GB update, but will have the Froyo software.

But, if you aren't having any issues with S-OFF and Froyo, you might just want to leave well enough alone. If you used the 2.2 RUU, you probably don't have root access, it's just your bootloader that is unlocked. So, it is just like Sprint intended for the 2.2 update.