As users search more, the length of their queries grow. This is a good trend for long tail publishers.
comScore data shows search engine queries continue to lengthen. Query length looks to be increasing about 3-4% per year. This may seem relatively slight, but the impact on the nature of search traffic is enormous, since keyword combinations are exponential.
While the math requires several debatable assumptions, I'd estimate that the 7% increase in query length during the last two years would increase the average number of possible keyword combinations by 25-30% for a website (assuming the site did not increase its amount of content). This trend may accelerate, since the longer the average query gets, the more exponential the effect.
Sites with extraordinarily deep content (ie: long tail friendly) should benefit most from this ongoing trend.
I'm composing a 78 word query now to celebrate!
The comScore post has other interesting data as well.