All notifications are not equal, but some of them are less equal than others.
I do want to wake up and take a call no matter what - I assume if someone's calling me, they really need me. But sometimes I can't take a call during a meeting.
I do need to take a look at incoming SMS - with less urgency, maybe. T-Mobile, for example, is known to send routine service notifications at five in the morning - I don't think I need to wake up for that. But if it is someone I know to be judgmental in their SMS habits, I'd rather take a look at what they wrote. Say, if my bank tells me there's fraudulent activity on my account - that's pretty urgent in my book.
I do need to know when mail comes - at day. I don't think I need that at night.
In other words, I need to be able to establish my own guidelines for what constitutes urgency, and introduce arbitrary classes of service - "anytime", "not when I'm busy", "not when I'm sleeping" and so on. Would be nice to have integration with Locale and IM status.
But today, there are only two, at most three, priorities: phone call, SMS, sometimes IM. This is not enough.