Clear offers something similar, however, I'm not sure I want to be advertising myself as an available hotspot. Sure, I can lock it down, but I'd still have morons hammering it in an attempt to connect.
There are many pros and cons to getting the service. While I do have access to DSL at my current location, I'm looking for something faster and Clear is advertising some decent speeds. However, as with 3G, cell saturation is a definite issue in areas where the company is heavily advertising for more customers. I suspect I'd be OK here, but traveling elsewhere in the area I suspect will bring with it the headaches associated with cellular data access. I like the idea of being able to be mobile on the notebook and still get access, but if I start running into issues with cell saturation, I'm not going to be a happy camper.
Ideally, I'd like to find someone close by who has the service and do an actual test. Maybe I'll "rent" the equipment initially and see how it goes. If it works to my satisfaction, I'll pull the trigger on getting the full blown mobile service.