i'm not sure that i agree with this at all. Microsoft, itself, has been having issues lately, and i don't think this is a Bing vs Google search thing. But i believe those issues are temporary.
Overall, the direction that Google is taking with its search engine is probably a bigger threat to Google, considering, i suspect, people really aren't going to like it.

lmao
edit: i was going to quote some interesting parts of the article, but, really, you should read it. it's all interesting!