While Pandora has recently been exclusive to the LG Incite, but now it appears, despite the reception page, anyone with a Windows Mobile phone can give it a go. As can be seen from the screenshots above, it likely only works on the AT&T network.
Apparently just by entering your phone number on this page you will have access to the download of this cab (in case you cant get it from there you can download it from here) and have the best internet music streaming service on your phone too.
Unfortunately on AT&T the Pandora is a pay service with a one-day free trial only, but at least you can play it in the background (I know, small consolation).
Download the cab from this xda-developers page here.