One of the critical roles Adblock has is to limit the number of obtrusive, offensive ads that display on a page. It's even in the welcome page that some ads will be allowed through when they are simple text-based or non-moving picture ads on a page, stuff like that. Something I've noticed, though, is that nearly none of even the unintrusive ads make it through these days, leading to the "disable adblock to continue" dilemna.
So to clarify my suggestion: I would like to see an option that allows us to mark an ad as "relevant and unobtrusive" when the ad is done right, to allow some leniency on the filter, even if it's just on a per-client basis.
This suggestion would allow more ads through that aren't disruptive, ease some of the tension between adblock and ad-supported sites, and I feel make the integration of adblock with the internet a bit more seamless where it would otherwise cut ad-revenue of sites that use such ads.
I understand this will probably not be a popular suggestion, especially to those wary of abuse by the very people that make such ads, but it has a lot of potential to take Adblock a step further in the right direction.