Like you, the idea of having support in WikiTalk for overloaded methods is very appealing to me. From a cursory glance over the code it looks like something would need to be done to extend the key for the hashtable of available methods as this seems to be the main barrier to supporting overloads, but obviously we'd need to get David to comment on how easy it would be. Equally I think that the wiki syntax is already pretty complicated and adding method overloads isn't going to make it simpler.

Actually, good news: WikiTalk includes support optional parameters already. This is mentioned a bit in WikiTalkMember, though perhaps not in much depth. I've added a few additional notes at OptionalWikiTalkParameters.