What's the difference between a hack built into a ROM and an app you download that lets you create a hotspot for tethering? Do these apps somehow hack the ROM?
I just searched the android market and there is a page full of tethering apps. Some say you don't even need root!
So even if you don't have it built into your ROM, there are still apps on the market that let you do it. I am surprise those are allowed to exist.