We're looking at better ways to let people know when they have achievements, including the option to get some pushed via email. But getting more of this to users who want it without annoying those who are highly focused on replies is a little tricky to balance:
- We don't, however, want to harass power users every time they get an up vote.
- We also don't want to become one of those sites with a million "subscription preferences", because over time those systems mostly get abused by companies who make it hard to unsubscribe:
"You only unsubscribed from the half-hourly updates; how were we to know you didn't want the "every minute" ones??"
At some point, we'll likely add "new privilege updates" to existing emails, but they would likely be part of the big-picture opt-in/opt-out emails.
We might consider some ability to add summary roll-ups that include rep or badges, but I doubt it would be a vote-by-vote approach, even as an option.