Just got the Mango update from Tmobile. Within the IE9 settings menu I can now choose who I want as my default search provider for IE9. Tmobile has some sort of agreement with Google and prior to Mango the default search engine for the HD7 was Google, but thankfully now they added an option to switch between Bing or Google. Not sure if other carriers have added this feature. It now gives users more choice options which is always good.