Traffic analysts Hitwise released new numbers today finding that Google's marketshare in US searches rose last month to an all time high of 67% of searches performed. Yahoo! Search (20%), MSN Search (5.25%) and Ask.com (4%) trail far behind but aren't insignificant either.

At this time last year Google was at 64% and MSN was at 9%. Momentum remains with Google, but is that momentum inevitable? Could things change? We've written about three ways that it could.

Innovation

Some have argued that Google's approach to search is outdated and slow to change. Apparently it's working just fine for them today, but there's a world of opportunities for other innovators to come up with a better search experience. We wrote about this situation in our recent post titled "How Vulnerable is Google in Search?"

Hitwise tracks 46 other search engines as well, which added up for a combined 1.7% of searches last month. 46 alternative search engines is like a week's work for our network blog AltSearchEgines, check it out if you'd like to learn about the rest of the industry, including some that may become the challengers of the future.

Semantic Web

Yahoo! is #2 today, but is taking the lead in support for standards based microformats and semantic web indexing. Yahoo! announced that it would index semantic markup three weeks ago. Since semantic markup could enable improvements in search quality by orders of magnitude, this could be a turning point for Google and Yahoo!

As we explained when that announcement was made:

Today, a web service might work very hard to scour the internet to discover all the book reviews written on various sites, by friends of mine, who live in Europe. That would be so hard that no one would probably try it. The suite of technologies Yahoo! is moving to support will make such searches trivial. Once publishers start including things like hReview, FOAF and geoRSS in their content then Yahoo!, and other sites leveraging Yahoo! search results, will be able to ask easily what it is we want to do with those book reviews. Say hello to a new level of innovation.

We'd like to get an update on the Yahoo! semantic indexing announcement, though, and presumably this is the kind of thing that Google will do soon as well.

Privacy Backlash

As Google grows continually stronger and more knowledgeable, the importance of the social contract between the company and its customers becomes increasingly more important. Google has not been as good as it needs to be about taking clear steps to guarantee security and prevent misuse of user data - including its own misuse of that data!

We wrote in February about how Microsoft's new levels of engagement with oppenness and data portability could offer an avenue to challenge Google, but few of our readers agreed in comments. You know what they say, though - if your mouth gets washed out with soap, you may be saying something important!

It may not be Microsoft that challenges Google, but it certainly seems possible that users will draw the line somewhere and look to limit Google's omniscience.

Perhaps not, though. Perhaps Google's search dominance will continue to grow and grow, month over month, year over year. Someday, if you want to know about your genetic propensity for a particular disease, you'll just as the Google. If you want to know what your kids are doing at home while you're away, you'll just ask the Google. Certainly today when we want to know what's on the web, a clear majority of us just ask the Google.