If it's just preset google searches, then it's no more useful than the current top-bar, and introduces clutter into the results page, which will make me switch

If it's just preset google searches, then it's no more useful than the current top-bar, and introduces clutter into the results page, which will make me switch back to one of the alternatives. However, if they're stealing a little bit of inspiration from MS/Apple and having definable 'libraries', that the user can specify, say "site:www.example.com" or "type:image filetype:png size:large" then it will be of quite some value.