Feel free to call it conservative, but I've always felt that success would come when the bridge was a good, old fashioned arch bridge rather than some futuristic levitating bridge.
Past attempts to bridge the gap have included huge redesigns (Windows 8) that worked on one platform but not the other (Windows 8) and have alienated swathes of the established user base (Windows 8).
Being able to use a synchronised app on phone and desktop that connects the two seems like a good solution - at the most basic level, being able to treat a window on the desktop as a second screen for the phone and file transferring would handle >90% of what I occasionally wish was easier while connecting the two platforms.