If you're visiting any Yahoo property today, chances are you'll see an "Upgrade to the new Firefox" link in the top-right corner of your browser window. The prompt also appears if you're using Internet Explorer, Opera and even the new Yandex browser. However, the prompt is missing from Safari, which will surely prompt a new round of speculation about Apple's rumored switch to Yahoo as its default search engine.
Given that Firefox now uses Yahoo as its default search engine, this move doesn't come as a huge surprise. Yahoo clearly wants as many people as possible to use Firefox - and with it its search engine (which is powered by Microsoft Bing).
A good deal for Firefox, but one has to wonder - how many people actually visit Yahoo properties who would also "upgrade" their browser?