I would like to request that votes determine whether features are done, and in what order.
What is popular is not always a good direction to take the site in.
For instance, there are a fair number of people that would like to be able to respond to an answer - ie, threaded discussion, or threaded comments, but that would detract from the main thrust of the site - questions and answers.
While the users define the community Jeff and Co. get to define the interface. The community can suggest changes to the interface, but if it doesn't mesh well with the intent of the site then it's unlikely to be implemented regardless of the community desire.
That being said, if you were able to get your idea voted up thousands of times, I'd be very surprised if Jeff turned it down, and that would only require a small fraction of the community.
Lastly, if you can get them to implement your feature, implement it yourself. For instance, Jeff was very reluctant to make a meta website or a place to discuss SO for months. It wasn't until shortly after someone else took it upon themselves to start a discussion board that Jeff relented (not wholly for that reason, but it was a consideration) and created meta.so.
There are several projects revolving around monitoring rep/vote/etc changes in real time, and while they have created the users/recent envelope, these projects still flourish because SO doesn't provide as much detail as some people enjoy.
I expect someone to add some social networking features to SO - allowing you to 'friend' other users, see their real-time activity feeds on multiple sites, etc.
Once the SO api comes out you should start to see greater interest in having one site that aggregates all three SO sites, but tied in with your accounts to you'll only see questions from topics you're interested on in each site. Eventually the API will allow posting questions, answers, comments, and voting and some people will never visit so - they'll merely be using their individual aggregate interfaces.
As these services start, though, you'll see many of those features being added as native features to SO.