What I'd REALLY prefer would be a way to categorize contacts into priority groups. Family/VIP, who can reach me 24/7/365. Friends who can call most of the time. Other contacts who can reach me daylight/weekday hours. And the rest who roll straight to voicemail. Add a schedulable exception (allow all calls in the next X hours because I'm expecting one from someone whose number I can't identify in advance).
Combine this with a visual voicemail (Google's product is good, but they already own far, far, far too much of my life) and I'd bitch a lot less about phones.
Increasingly: voice calls are very distracting and annoying. Unless you've got very good reason to call me, don't. I don't even get to "please don't call me" any more, I'll simply hang up (on the rare occasions an unwelcome call gets through).