That's correct about the list. Even though there's a circular, something like 65% of the ATT locations will email you when there's one available for you...I read this on maccentral.com. I don't think the stores will confirm it, but if you walk in and ask, they might do it. They did for me.
http://www.macworld.com/news/2007/05/24/waitinglists/index.php
re: data plan... I think you're right. I currently have a Treo600, but no data plan because it was always too expensive. I would on occasion send an email in an emergency. I tried using the web once and it cost me something ridiculous like $3 for 10 minutes-forget that. I'm really looking forward to having a phone with WiFi though.
Dave