I recently tried to visit http://new.m.yahoo.com with my Google Ion Android developer phone and got this: "We are sorry! Your phone does not (yet) support the new Yahoo! homepage. Please check back later."
The new Yahoo Mobile worked fine with my G1. Shouldn't the Ion, which uses the same browser be supported?
The Ion's user agent is: Mozilla/5.0 (Linux; U; Android 1.5; en-us; Google Ion Build/CRB43) AppleWebKit/528.5+ (KHTML, like Gecko) Version/3.1.2 Mobile Safari/525.20.1