We'll just pass then the mic and let you tell us what you think in the comments!
We absolutely will offer MMS on iPhone 3G S in late summer once we complete some system upgrades that will ensure our customers have the best experience with MMS. These upgrades are unrelated to our 3G network. When MMS is ready, we will let customers know.
Regarding offering a tethering plan:
We plan to offer one but we don’t have an announcement to make at this time.
AT&T Corporate Communications
[Thanks to Phil for bringing this one home!]