I'm sure some of the experts get somewhat annoyed by easy questions... or that some of the novices don't want to see the advanced stuff because it would just confuse them... etc... so I think giving people the ability to filter (or simply easily differentiate) questions by difficulty and time-required might be well-liked.
Of course, "difficulty," is somewhat subjective, but the idea is that the person asking the question would rate his/her question based on how hard it would be for an expert in the areas relevant to the question, (e.g. for an expert C++ programmer that has experience writing operating systems.)
On the front-end side, users could completely filter the questions they see displayed (e.g. only "moderate" and "hard" difficulty questions would be displayed, or only "easy" questions would be displayed,) or if they chose to not filter them out, they would simply see a little green (easy), yellow (moderate), or red (hard) circle near the question title on the list of questions.
In a similar same manner, a "time-required" classification could be implemented. This would be used to differentiate questions that can be answered quickly vs. code snippets that are long or questions where the answers will be an elongated, back-and-forth discussion. When users ask a question, they would have two combo boxes there to fill out -- hours (1 to "12+") and minutes (15-60, 15-min increments.) On the question list page, questions would be filtered out entirely by the time required to answer them, or they would be displayed with a little clock (or circle): for a 15-min question, 1/4th of the clock (starting from noon) would be made green... for a 30-60 min question, the appropriate amount of clock (50%, 75%, or 100%) would be filled-in with yellow... and anything an hour or over would be painted in red, where 1h10m-2 hr=1/6th of the clock, 2-4 hr=1/4th, 5-7 hr=1/2, and so on.
I'm new, and I'm not sure it would be worth implementing, but I just thought I'd share the idea.