Update: Pandora is walking back the earlier Tweet a bit as can be seen above. Like always, we need to treat Tweets as extension of customer service, but not necessarily the company line. Here's to hoping that Pandora has something in the works.
In a nasty blow to Microsoft and despite their wooing, it looks like Pandora is going to sit on the sidelines for Windows Phone 7--that is until demand makes it hard to ignore.
In a recent Tweet, the developer said that "they don't have any plans for a WP7 app" which is sort of strange since they were announced as a launch partner. One would think that no-background play may be an issue, but they certainly had no problem kowtowing to Apple over that one. We also know Microsoft often offers to pay for the development of high-demand apps, so we don't know what went wrong here.
Alas, the saving grace is there are alternatives on the market e.g. Slacker Radio. Once Windows Phone 7 gets "Smart DJ" functionality, we'll see less need for Pandora anyways.