It's the same way with Windows mobile feature called internet sharing, mogul and touch both use to do it without a PAM plan on the account after that new ROM both have been disabled and now you're required to add the PAM plan. Sprint can do it. They're entittled to stop your stealing of their service lol
There are ways around it, if you do it manually instead of the easy phone feature. All you have to do is use it as a modem instead and dial the sprint data number (#777) and you are online. The phone still doesn't report that it is tethered, all they did was restrict an application feature via provisioning.
I have a BB 8830WE on the SEP and use it as a modem all the time, never had to add it to the plan and it has always worked. I actually just always thought it was included.
I'm fairly new to this so I don't claim to be an expert by any means but I do take a very common sense approach to anything I deal with. If you have the "Simply Everything" plan and you can access the web with unlimited surfing, then what is the difference whether you are doing it via your phone or through your phone via your laptop? I don't see that it should be any skin off of a carrier's back?
Look on crackberry.com for instructions on how to do it. Any Blackberry can do it, on just about any data plan.