The large database company example is especially telling. The company I work for chose Java mainly for the benefit of a large talent pool, but we have great difficulty hiring people. I think it's because we're in the middle of nowhere and don't pay Silicon Valley wages. I think if we had chosen a more "offbeat" language (to borrow mosburger's adjective) we would have had a novelty factor that would increase interest in the job. After all, we're doing interesting stuff, but our technology decisions make us seem very dull.

Edit: Please note I don't have the authority to make a technology change and see what the effect would be on our hiring, despite the good ideas of those replying to me.