QUOTE(Peter Damian @ Sat 5th February 2011, 2:16am)
Well, I'm not sure that this is the relevant way to frame the question. I can certainly think of some institutional improvements which I think would make Wikipedia better - flagged revs, term limits for admins, higher thresholds for both notability and reliable sources, giving content editor more say in "judicial" matters, creating better incentives for existing article improvement rather the creation of new articles, and a few other things - but at the end of the day I'm not so sure that all these would add up to make it a real encyclopedia.
I think it'd be better to focus on the *how* of making it better rather than the *what*. In that regard I think the main thing is the complete lack of competition that Wikipedia faces. Part of this is just due to the inherent structure of the internets (this "critical mass" people have brought up - in economic terminology, "economies of scale" and "path dependence") and part of it is "artificial" like Google slapping Wikipedia links on top of its search pages. So in a way, I'm not quite sure what the exact policies that would make Wikipedia be better ARE, but I am pretty sure that if it had to compete for readers/editors with other free online extensive coverage encyclopedias it WOULD get better one way or another (or DIE, but then it'd deserve it and we'd all be complaining about whatever it was that replaced it). At the end of the day it's not that Wikipedia is really that awful - it's mediocre, really bad in some ways and even occasionally "good" in others - the problem is that it has such a monopoly in the market it serves.
If you owned Wikipedia, what would you do with it
Peter Damian If you owned Wikipedia 
