So Spotify for Windows Phone 7 is supposed to land today, and we're refreshing the Marketplace like mad to spot its arrival. We've heard tell of some bumps in the road, however, so there's a possibility of delay. In the meantime, Microsoft gave me a quick look at the app. It's completely integrated into Windows Phone, including a display on the lock screen, a live tile, and a little notification hover that lets you control playback. The app itself looks entirely native, and seems a bit more polished than Rdio's own effort. Buffering was pretty fast over Microsoft's Wi-Fi, and I was all over the app in seconds, diving through my PR rep's playlists and the week's new music more intuitively than the desktop app, which seems dated in comparison. There's a Cover Flow style of skipping through tracks on a playlist, however, that looked nice but didn't seem very useful. We'll keep you posted on when the app arrives on Marketplace, and will dig in deeper then.