It's strange to hear that from a Google fan-boy, but I like Bing a lot!
The pic-of-the-day idea (an evolution of Google doodles) is ingenious. It forces me to visit Bing every day to check out the latest pic (plus it makes a great home page in my browser).
The video / image search is great too. The infinite-scrolling feature really makes browsing images so much easier. And the live preview of videos is useful as well. The maps have some interesting features (birds view) and they provide full details in Cyprus as well (Google Maps in Cyprus are a joke).
Since yesterday I started using the new twitter search, it seems to work great.
All, in all, I really like what I see: a fast, beautiful and useful site.
PS: but of course I 'll still be using Google as my main search engine.