If they were to have the expression trademarked ... which might be tough, then you would have to answer three questions. Is there any chance that your site will be confused with their product? Will you benefit financially because the names are identical, and one other I can't recall !!!
If you are really interested, google up the story about the guy that bought AAA.org. Of course AAA sued him. He lost on the first two criteria, but he won in arbitration because he had a legitimate service that had absolutely nothing to do with the auto AAA and there was no chance that someone was going to find his site and use it thinking they had found the original AAA. [Amateur Astronomers Association of New York]
I use this rule if I'm thinking of buying, selling or developing a questionable name. I make sure that I don't put a lot of time and effort into a name knowing that someday, someone could simply take it from me.
Concerning value, at the moment it's worth about $5000 (retail) but I'm sure most of that value is coming from searches for google's chrome.
I wouldn't develop it for a few reasons. It's already drawing value from Google. It won't go anywhere without Google ranking. If Google wants to eliminate the problem, they won't have to sue you, they'll simply remove the site from Google searches and give you the runaround until you give up.
I usually sell names like that and let the next guy take the chance.
I hope all of that makes sense. My brain is mush at the moment.