It's the only thing they have in the online/offline integration space. If not a direct competitor, it still has relevance. Google doesn't use Flex or Silverligh

It's the only thing they have in the online/offline integration space. If not a direct competitor, it still has relevance. Google doesn't use Flex or Silverlight because they can reproduce complex interfaces in just javascript and it's usable offline with Google Gears. If Google wanted to compete with Flex/Silverlight, they could release a GUI widget toolkit for javascript and combined with Google Gears they would have a contender.