Opera has decided to switch to using WebKit and V8 for for all new products. First they'll start with a product for smartphones (since as they say, many mobile-facing sites are only/best tested on WebKit anyway), and then Opera Desktop and other products will follow.
By my count, that leaves us with three major rendering engines (WebKit, Gecko, and Trident), and three major JavaScript engines (V8, SpiderMonkey, and JScript). Well, you could perhaps argue that there are two JScripts (the really broken one in IE8 and earlier, and the much better and completely rewritten one in IE9 and later), but let's not quibble.
