On the issue of charging for OS upgrades for the iPad, we'll have to wait and see... However... The iPhone gets "free" upgrades. The iPod Touch requires payment. This is NOT purely a choice on Apple's part. It's an issue of how revenue is recorded for the devices and laws surrounding the issue of adding additional functionality to these devices. The iPhone is monetized over time due to the required service plan. The iPod Touch is sold outright. There is a difference in the way the IRS looks at these things and what laws and FTC rules apply due to the difference. This is a little bit of an over-simplification, but I think it accurately reflects the situation.
Given this, I think it's fair to say that we will probably have to pay for Major OS upgrades (as is the case with OS X, by the way) but will not have to pay for point releases.
I don't have a problem with this. I'm buying the device in the form it's in. If I want the additional functionality, I'll pay for the upgrades. If not... well... no one is holding a gun to my head (or wallet).
You're right gentlefury. Unlike some software companies who shall remain nameless <coughmicrosoft>