Quite a bit, actually. Since 2007, we've gotten Javascript JITs, Canvas, WebGL, consistent box models, consistent event models, flexbox, CSS transitions & animations, CSS transforms, localstorage, IndexedDB, websockets, HTML5 audio & video, history.pushState, and several other features. And components (custom elements + Shadow DOM) are coming, and already implemented in some browsers.
Pretty much anything you could do in a native Windows app in 2007, you can do in a webapp now, except pwn your computer. Only problem is that the goalposts have moved: now everybody expects you to be able to do it on a phone as well, as well as access the camera, accelerometer (which you can do on the web, actually), contacts, calendar, and bluetooth hardware.
Yeah man. I've never heard of those. They sound like the best thing since sliced bread. Only if they could access the DOM...
Seriously... what are you even talking about? Why do you even mention them? You read single threaded and thought "Quick, I must come up with an answer! I can't let a stranger on the Internet change my opinion!"?
Their arguments are just as valid as then. Web interfaces will never be as rich as desktop ones. Cloud connected desktop applications will gain a lot of momentum going forward.