From Business Insider:

it activated 400,000 to 500,000 3G iPads during Q2 (Which is in two months since the 3G didn’t ship until April 30th). It’s “surprising” how many business customers are approaching AT&T about the iPad. Whereas business customers were famously skeptical and reluctant about the iPhone at first — and have since warmed up to it — they are apparently very eager about the iPad. AT&T said a lot of companies have iPad trials going on, and many see opportunities to use the iPad in their business as a laptop replacement. Look out, Microsoft iPad users are using more data per month than the typical iPhone customer, but less than the typical laptop-card customer, which makes sense. 75% to 80% of the iPad 3G subscribers are at the more expensive ($25/month) AT&T 3G data plan. Overall monthly bills in the $25-$30 range, including early customers who signed up for the $30/month unlimited plan before it was discontinued.

Gizmodo notes that AT&T has improved call quality in New York and upgrades in San Francisco are on the way.  AT&T has the PowerPoint to prove it.