A while back I'd posted some comments about wanting to compile a list of online Christian resources.  It turns out my scholarly brother-in-law, Michael Ludwig, has done a lot of the work for me.  He recently got a job doing sermon research for pastors, so I figure it went along with that, but he kindly passed the following list along to me a little while back.  Here it is with a few bits added.
 

I prefer the NRSV, which Bible Gateway doesn't have.  So Oremus is a NRSV passage search.
http://bible.oremus.org/

This is a solid source that has articles written by scholars on a wide rage of topics.  Then have a decent section on mission that made me think of your idea of pooling articles.
http://www.religion-online.org/

I haven't used this one, but it looks solid.  It has everything Reformed, but also a page on mission.
http://www.monergism.com/thethreshold/articles/topic/missions.html

The lazy-man's way of reading the Greek NT.
http://www.zhubert.com/

Great source for reading Church Fathers.
http://www.earlychristianwritings.com/

Scott Sunquist's site that suppliments his book (History of the World Christian Movement Vol 1 & 2).  It has a good glossary of terms and people, timeline etc.
http://www.hwcmweb.org/hwcm/holder.htm

Another site that has general but more detailed descriptions of Christian figures and terms.
http://mb-soft.com/believe/indexaz.html

A great source for the writings of the Reformers and even has some 20th century writers like NT Wright.
http://homepage.mac.com/shanerosenthal/reformationink/index.htm

I can take credit for coming across one site called PresbyMergent.  It's not an academic site, but is devoted to the Emergent/emerging church in the PCUSA.  It has a good bit of theological discussion and I can vouch for a couple people involved with it, so I think it's worth including.

Thanks for the help Michael.