There's plenty of proof that if there was something better, they'd change it. "HD audio", different sample rates etc - nothing has replaced 44.1. I don't think it's down to simple indifference to doing so. We've seen our DVD recorders and players go to PVRs, and TV go from analogue to SD and HD digital (no mean feat, given the buy-in required of broadcasters AND manufacturers), and TV go from cathode tubes to plasma and LCD. Not much stagnation there - when the newer option is clearly better.