Search Box within Google Search Results - teleportation

In early March Google started showing a search box within search results pages (SERPS) often in response to major brand searches, e.g:

NASA
Argos
FT
Times
Telegraph
Guardian

The official Google announcement clearly felt it was another improvement for user experience. Others are more skeptical, claiming it will cause users to spend more time on Google whilst being exposed to competitive ads and less time searching on the branded site they first searched for.

We expect most large sites to obtain this search box over the coming months as the Google algorithm adds it and we expect it to be enabled or disabled in Webmaster tools under Sitelinks.