Pocketnow have been conducting various comparison tests between WP& and other devices. There are comparisons of Startup Speed, Email experience and Browsers. An important caveat to note is that the Windows Phone 7 devices are not final hardware or software, so there may be changes before launch. Check out the videos below and visit Pocketnow’s YouTube channel for more videos.
Startup Speed (WP7 vs HTC HD2 vs Google Nexus One vs iPhone)
Browser Comparison (WP7 vs iPhone 4 vs Google Nexus One)
Email Experience (WP7 vs Android vs iPhone)