Microsoft’s new search engine Bing–which debuted at our D7 conference last week–unexpectedly went live this morning ahead of its scheduled June 3 launch date and it’s already done much to distinguish itself from Microsoft’s previous efforts in search.

Certainly, there’s far more verb potential in Bing than “Microsoft Live Search,” the service it’s replacing. And–beyond all this silliness about Bing’s prowess in adult entertainment queries (ever tried a similar search in Google (GOOG) or Yahoo (YHOO)?)–there’s a lot to impress. Bing is fast–very fast, actually. Its local results are robust, accurate and usable.

This search for “pizza near 94117,” for example, returns not just a list of pizza parlor homepages, but phone numbers, directions, reviews, coupons and bird’s eye maps as well. Video search is deep and the ability to further calibrate it by length, screen size and resolution is a nice touch. It offers a 411 service similar to Google’s.

And it’s UI is sleek, although the choice of hot air balloon background is begging for a wisecrack. There’s plenty of hot air in Microsoft’s claim that Bing is a “decision engine, designed to empower people to gain insight and knowledge from the Web, moving more quickly to important decisions.” That said, the engine does seem to be delivering, at least initially, on that promise.

Question is: Can Bing boost Microsoft’s market share in search from the mid-single digits to something more respectable?