P.S. One more thought. How long do you think it will be until the 2 GB plans for the iPad are back up to $30? I think they only dropped it down to $25 because if they hadn't, the resulting storm would have made hurricane Katrina look small.
The real winners are now the JB/mifi users. You can keep the unlimited data plan on your iPhone (since you will not be officially tethering) and have all the 3G you want on your iPad.
Winners? What sad win that is. Unless you to keep your iPhone forever that is.
Because I bet if you want the new iPhone 4G, you'll be forced to leave your current, unlimited contract too. So that's a temporary win at best.