I'm not sure if this is how Bing will kill Google, but I do think Bing is going to slowly take a lot of market share away from Google. How? Niche specific search customization.

For a while now I've been bugged by how searching anything on Google is done with nothing but one text box. There's no customization. You can't tailor your search or refine it based on values and properties specific to your categorical search. I think Bing recognizes that and is gunning in that direction. Their restaurant finder lets you filter out restaurants with dim lighting, for instance. You can't do that with Google. And if Bing keeps adding various categories to their search, I'm willing to bet that it'll be a lot more useful than Google.