I just read the Business Week article on Google (BW, October 12, 2009, p44) and believe it misses the key point the threat against Google is that its search just isnt very good. Unfortunately no one is yet much better. Someone will be, and it may be Google itself, but I believe it is just as likely to be another startup.
First, a little background. I was the first General Manager of Microsofts search group in 1995. That was at the beginning of search and almost all of the players lost their way. Microsoft focused on its shows, believing that content was king. Yahoo believed it was a portal. Alta Vista couldnt decide what it wanted to be. Etc. I knew at the time that finding what you wanted on the Internet would be a daunting challenge. It would be hard to distinguish your search intent from a key word or two to deliver a result that both high precision (missing no positive searches without lots of false negatives), while prioritizing the search with the responses that really met your intent.
What Google has done exceptionally well is keeping its search simple its interface is clean, uncluttered, and easy to use. Comparing it to Bing, it is easy to see why it remains on top.
What it does poorly: giving results that match what its users are really looking for too many irrelevant results. Why? Its core page ranking thesis. Google believes that the most popular links are the ones that are most relevant. This is true sometimes, but equally false at other times.
So.. where does this go? I believe that some very clever work will be done that allows for more precise search results based on a better algorithm than page ranking. Who will do this work? My bet is on a startup, where NIH isnt a factor.