Well, if you wanted to make a project of it, I see a couple ways to go.
Spend $25 on Sunshine to get SOFF, and run the RUU for the US (or internantional, or whatever country) for the unlocked developer version of the phone. That will not be root, so you are compliant and legit, and there is no carrier bloat. You do this, and you do sort of take future software support issues unto yourself, so file that away.
If you want to be silly and risk your job by being all phone hackerried, I have heard of applications that allow you to hide the fact you are rooted from other applications. Rootcloak.