A few days ago I loaded up IE6 on a company machine (to download Firefox, natch) and noticed that Google displays a message on the main page, in a box in the up

A few days ago I loaded up IE6 on a company machine (to download Firefox, natch) and noticed that Google displays a message on the main page, in a box in the upper-right corner, encouraging me to download Chrome. It doesn't seem to appear using any other browser. So they're getting pretty close to doing that; perhaps less obtrusively than you suggest, but the intent is there.