I currently use AT&T's MiFi 2372 device as my only source of Internet connectivity at home. I do work out of my home, and I use Nortel VPN daily. I have never had problems connecting to our company's VPN with this device or the 5GB plan for mobile hotspots. (Although, I do usually use about 7GB/month.)
I am considering changing that device to the iPhone 4 so that I would only need one device for Internet tethering and my phone. I will not need to access my company VPN/email/applications from my iPhone, but I will need to be sure that I can VPN on my laptop. I will have to use the iPhone tethering to accomplish that.
Am I going to be forced into paying for the more expensive DataPro Enterprise with Tethering, or will my VPN on my laptop still work with the Personal plan?
Even though some of the applications you plan to use your personal hotspot for might fall under the enterprise data package AT&T sells, I wouldn't volunteer to pay more money than you have to. I would sign up for the DataPro 5GB for iPhone 4 Personal Hotspot for 50 dollars and see if anyone complains about it.
I had hoped the enterprise data plan was something AT&T would force companies to pay for when they are giving company phones to employees for business use, but not the average customer with an individual responsibility account. Maybe someone with more knowledge than me will post a more definite answer.