I think what would be extremely beneficial is if there was a way to have a row of buttons at the bottom of each post to mark posts as useful in 1 way or another and the ability to filter to just these posts easily.
I would imagine the buttons being something like:
[How-To / Tip](0) [Bug Report](0) [Bug Fix](0) [Question](0) [Answer](0) [Useful / Mirror Link](0) [Request](0) [Update](0)
Number representing how many people tag for the post for each category. Allowing for it to be voted for more than 1 category.
And then at the top of the post page, you could filter the posts to just see 1 or more of those categories so you can quickly find information that you're looking for (along with an option for minimum number of votes requirement and the ability to sort by most votes).
I think this would drastically reduce the number of repeat questions and make it much easier to figure out solutions to problems. Not to mention the devs could much more quickly find bug reports and problems people are having.