This is a key insight. Design isn't any more or less "important" today - it has simply become a more critical place of battle. If two products are even in terms of features, design can be the tiebreaker.
Design can be even more critical than that and more valuable than feature parity. Facebook had way less features than Myspace - you could do all kinds of stuff on Myspace like listen to music, customize your page, have photo slideshows - but Facebook's design was a welcome relief from the haphazard Geocities-like mess that Myspace devolved into.
And similarly, Facebook's current crowded interface leaves room open for even better designed networks like Path, Instagram, etc.