Thread is a little stale, but I have some info that might help anyone having problems...
While I've not had to do it with my EVO (root'd and WiFi Tether - both still working as of June 12th) On some of my other phones, I had to Jailbreak my iPads (V1 64gb 3G, V2 32gb WiFi) and install iBluVer, which initiates a standard Bluetooth DUN session (on sprint you'll need to pay for PAM or disable the tethered phone's NAI, most phones the latter is just entering a password and choosing "dissable NAI")
I would like to note though, that I've have very mixed success with 4G tethering, sometimes it works, sometimes I get *painfully* slow speeds (like 200kbps), and sometimes it does not work at all. (But this is in a nearby city that sprint doesn't even list on their website as covered, so it may just be a "testing" tower or something)
Also, I'm not sure if this works because I never tried it, but I've read that the EVO can tether over USB without root, for a one-time fee of $20 or $30 you can buy a hardware device called a "Cradlepoint" which dials up the internet on your phone over USB and creates a wifi hotspot itself ($20 version requires AC power, $30 version includes rechargeable battery)
Lastly, I cant remember if it was said on here or elsewhere, but the general consensus is that Sprint is only terminating service for 100gb or more per month, so if you stay under that (I've done upto ~30gb a few months without issue) you should be safe. If your a heavy user keep an eye on sprint.com to check your data usage.