To each his own is the way to go, but are you going to be carrying around your iPad in your hands all day? If so, then by all means pony up and pay the extra cash for the iPad 3G and the monthly service costs as Apple and AT&T sure need as much money as you want to give them!
Yes, waiting a couple of weeks to buy until the 3G iPads are released is not a long time, considering that human beings have lived on this Earth without iPads until last week, but it's really more about not spending more money than you have to than waiting longer to get a 3G iPad.
Maybe you're rich and giving these companies more money than necessary is no big deal to you. If you're not going to be carrying around the iPad in your hands all day and not rich, then getting a iPhone battery pack that is a great choice if you're carrying your iPad around in a bag.
The battery pack that I've mentioned in my previous post is the best by the consensus of others from a MacRumors thread of iPhone battery packs, and as long as you remember to charge that battery pack one time, that charge provides you for at least 6 recharges of your iPhone!
It requires very little effort to jailbreak ones own iPhone and turning on or off the mobile hotspot also requires little effort. You can also just keep your iPhone in your bag all day connected to the charger and only disconnect it from the charger if you have to make or receive a call.
And to be realistic, how many hours in a day will a person use their iPad in an area where there is no WiFi connection available? Most people have WiFi in their homes as well as in many businesses, and so if you happen to be in a non-wifi area for a while it's not a hassle to tether.
Furthermore, who knows what the battery life will be like on the 3G iPad? Apple is claiming 9 hours, but what if Apple really didn't release the 3G version early because of an FCC approval delay, but are actually releasing it later because the WiFi version has a much better battery life?
Perhaps when everyone buys their 3G iPad's, they'll find that the 3G model battery drains at a far faster rate than the 9 hour claim. You may find yourself not only paying extra for the 3G iPad + $30 each month, but you'll also need to carry around a battery pack for your 3G iPad!
Yeah ... carry around an extra battery pack ... make sure it's charged and on you whenever you might possibly need it ... jailbreak your phone if you haven't ... then sit there with your iPhone on a table plugged to a battery pack ... click the right buttons on both devices to start the tethering ... If the $15/$30 per month is really distressing, that will work. Just puzzled why people want to take a device that exists to be simple and go down this route.
Being able to buy an iPad today vs. in a couple of weeks seems like a non-factor to me. A couple of weeks is not long.
To each his own.