I'm all for new content. I don't have to agree 100 % with it to find it useful. Luther's commentary on Romans would be a good example of this. So Calvin's would be welcome by me. (If you're already providing the Geneva footnotes, do you really feel you need to ask about providing Calvin's comm.? )
It should go without saying that I don't mean anything which lies outside of mainstream, orthodox Christianity, generally speaking. And, of course, historical material has value for academic pursuits. For example, I'm not a Catholic and no fan of their doctrine, but I wouldn't be opposed to Augustine's confessions or even the writings of Aquinas. They have some historical value, especially Aquinas with respect to philosophy and ethics. But not the latest babblings from the most recent Mormon prophet, etc...
You get the idea, I'm sure. I guess it would depend in part on how wide you want to define the role of providing a tool which helps the Bible student study the Bible.
I think Online had available some modules of cult material, given with the understanding that they were not endorsing it, but providing it as a service to help equip the saints with knowledge, I think with the eye towards helping us fulfil verses such as Phil. 1.7, 17 and 1 Pet. 3.15. (I could be confusing this with some user created material, again provided not as being Biblical but helpful to the saints in our witnessing efforts).
So some historically based material like that might be useful, too. I would certainly understand why you might shy away from providing it via the official channels. Might be a good user-mod project for a budding apologist, who had the time, interest, resources and inclination.
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