I wonder if OS 4.0 for iPad would coincide with the release of the second generation iPad.
Exactly. iPhone os 4.0 will probably be optimized for ipad v2. Sure, the current ipad will be able to run it, but it will run it just as good as the iPhone 3G runs iPhone OS 3.0 (it runs it, but nothing show stopping).
The fall upgrade will likely be in 6 months, the next gen iPad will likely be a minimum of a year... So another 6 months on top of the wait for 4.0.
I'd say, buy it now if you want it... If you wait on technology, you'll always be waiting for the next best thing.
We have no idea when the new iPad will be out, but I doubt that it would be this year. Also apple seem to wait two generations rather than one to make their hardware obsolete. So this generation iPad will do everything in 4.0, but not necessarily everything in 5.0.
1. I didn't know Apple said they won't charge the upgrade fee.
2. I didn't know the fee is only $10. I thought it's more like $30 or $35, but I now think waiting 5 months to save $30 is not worth the wait.