"For now this will be a no-fix due to licensing issues. All libraries that we host on the Google AJAX Libraries API
are offered free of charge with very liberal licenses. EXT, however, requires a fee for users wishing to use it
commercially. We like to keep the libraries consistent so that we don't put our users in a dangerous situation
where they might be liable without knowing it."
Jack insists that ExtJS will be up on Google Code stating
"Ext JS will be up on Google API in the near future. :)"
and then says
"No news yet guys. I'm not sure what the hold up is."
"This is contrary to discussions we have had with them. I will check into it and find out if that is accurate."
Well, you want to know what the hold up is about? Google said it best :
"For now this will be a no-fix due to licensing issues (with Ext)."
Source : http://code.google.com/p/google-ajax-apis/issues/detail?id=50#c44