Firefox does this too. However, I notice a difference sometimes in the site you are taken to. I mean to make an article about this when I get time. Common words like "adobe" will always go to the obvious site, but other words must depend on who paid what to whom. :)
I see only advantages.
Don't forget you can also set up keywords in Opera and Firefox, to go straight to sites by just typing in a word you choose. Eg: "456" for the site 456 Berea Street.