Yes, but hardware will actually become cheaper and faster, not more expensive and slower and therefore hardware resources also become less relevant. The terms of the tradeoff actually change in favour of "easy" development frameworks. It is true that Java will benefit from this more than Ruby and friends will, but that doesn't really change the reasons people choose these anyway (because it is not about performance, it is about labour).
Yes, but what is the state of the art of most server-side web apps, really. Even the most successful web apps don't do all that exciting stuff. Most are just pushing data around and perform well enough with whatever tools you throw at it. In many cases performance is simply not that much of an issue compared to other factors such as development speed.
Javascript is a front-end technology and therefore it is really different and not really suitable for comparison in this case.
