It's certainly a trade-off, I wouldn't pretend otherwise, but the vast majority of assets I produce at least are vector, which are then translated to various sizes of bitmap image, which is wasteful, painful and ultimately futile as there are still issues whenever a new device comes out (like the iphone 6).

The pixels of the screen are now so small they have almost disappeared, so I think there's an argument we have reached the place where going mostly vector makes sense.

Clearly some assets will always be bitmaps (photos), but so many others are not well represented as bitmaps (icons, text etc) - content is fine as bitmaps but controls and chrome are usually better as vector.