Consider a diqus like platform. How cool it will be if formatted comments can be served directly from the database.
But she said that they will be available through plugins. So we will have to wait and see...
The node js addition is to leverage the speed of v8 engine that impacts only the view building time and not much else(I could be wrong though)
V8 and Spidermonkey are on par in the way we are using them. Node/V8 just gives us a little more flexibility and less C code to wrangle so we can make the view server better faster :)
Either way, with the in-progress plugin model, many of these niceties can be easily brought back into any installation, should they be moved out.