Kurzweil's association with the topic of "singularity" could turn into bad publicity for the company. It is regarded at worst as lunatic fringe by some, even within the tech community.
co-founder Paul Allen is one who has been highly critical of the idea.
There is the final possibility: that something bigger is indeed going on, a project or two in the works that Kurzweil will help bring to fruition. Let's say there's a good chance it could materialize in six months but an equally good chance it will take six years, or won't materialize at all.
If I were Google, that would reason enough to keep my mouth shut now.
My best guess here is some combination of all four. The company is betting that Kurzweil's idiosyncratic personality and less-than-perfect name recognition will permit it to say as little as possible, thus avoiding fueling speculation about projects that may not pan out while also skating gently past any media volatility stemming from his involvement in the singularity movement.
At the same time, regardless of his level of direct involvement, having him there will undoubtedly spur the engineers in Google's labs to do their best work.
--Written by Carlton Wilkinson in Asbury Park, N.J.