They seem to be using their own javascript engine, so it might need separate testing because of that. Although if it becomes popular enough, most javascript libraries and frameworks will surely support it.
There are actually very few inconsistencies in browsers implementations of the JavaScript language, it's the DOM that's the problem. If all they're doing is swapping out the engine for a JavaScript 1.5+ compatible engine, then we should be fine.
You can bet they will. The V8 engine is unlikely to present much of an obstacle. We have a large JS codebase and the Opera, WebKit (Safari), Spidermonkey (Gecko/Firebird), Rhino (Spidermonkey port to Java) and JScript (IE6/7) engines are no hassle to support.
The hard part is DOM interaction and styling. But as they're using WebKit and are putting a lot of effort into compatibility - this should be a breeze.
The really hard work is support for IE6. 1990s JS assumptions, very bad and inconsistent DOM behaviour, etc.
New, open JS engines with a different take on executing JS (Tamarin, V8) are wonderful news for JS developers everywhere. And consumers too, of course.
I know the portion of IE6 on the web is still around 25%.. but do you know what portion of your customers is actually using IE6 still?
I wonder at what point it is justified to return a 'please update your browser, preferrably to one of these: [list of reasonable browsers]', just because of the effort it takes you to keep IE6 compatibility.
any link to V8 project? Comic strip says its just a module in Chrome and can be used extensively for other projects i.e. that means games/cool desktop/mobile apps