Wikipedia is, at this point, truly "encyclopedic" in that it covers all manner of topics, but I think it still has a loooong way to go before it can consider itself the universal reference.
The primary problem, as I see it, is consistency of voice/target audience. For example, many math topics read as if they are the intro section of some Mathematics graduate student's thesis, whereas most biology topics read like some high school biology student's book report. Compare the article for "Markov Process" (http://en.wikipedia.org/wiki/Markov_process), which starts with a nice introduction but quickly devolves into foreign symbology, to the article for Caspase 9 (http://en.wikipedia.org/wiki/Caspase_9), one of the most important components in the process of apoptosis, itself one of the most importent processes in growth, development, disease, cancer, etc...which has barely 4 sentences and a dozen references.
I think this is definitely a cool concept for the future. A goal of making it so that articles have sequential and mutually hidden content. Click on "introductory" and you see an article written using less jargon and more high level overview information. Click on "academic" and you see an article written for someone at a sophomore level in college. Some math, some jargon, but without an expectation of prior domain expertise. Click on "expert" and you see an article with domain specific jargon, appropriate as a reference for someone who already has a great deal of experience with the subject matter.
It seems to me like that kind of end goal would also provide a better balance between editorial choice on how much detail is appropriate and providing a smorgasbord of information that potentially overwhelms the audience.
I think it's great that some universities are asking doctorate students to include one or a few wikipedia articles as part of their published work.
We really do need more experts writing wikipedia articles. Even if they just spend a month or so writing a thorough (if biased in the sense of there being just one or very few authors) -- a good first draft is much easier for others to come in and comment on. And veterans in the field might not find the time to write an introductory article for scratch, but they might have the time to read one, and comment...
This is a great place to plug the importance of the Simple Wikipedia section. The main wiki page for a complicated idea shouldn't be dumbed down, but there can be a coexisting version using simpler language. Explaining something simply is often an exercise in how well you truly understand a concept.
I'm guessing other encyclopedias have similar weak points. Wikipedia is a truly fantastic resource, not just for academia, but for the world, and we need to hold it up instead of beat it down.
The primary problem, as I see it, is consistency of voice/target audience. For example, many math topics read as if they are the intro section of some Mathematics graduate student's thesis, whereas most biology topics read like some high school biology student's book report. Compare the article for "Markov Process" (http://en.wikipedia.org/wiki/Markov_process), which starts with a nice introduction but quickly devolves into foreign symbology, to the article for Caspase 9 (http://en.wikipedia.org/wiki/Caspase_9), one of the most important components in the process of apoptosis, itself one of the most importent processes in growth, development, disease, cancer, etc...which has barely 4 sentences and a dozen references.