A question & answer content type would be really useful for asynchronous and persistent knowledge sharing. Many intranet and community platforms have this feature, so it makes sense for Linchpin to include something similar in order to compete and provide a comprehensive communications product. The format could be built off of Microblogs; we essentially just need threaded conversations which can have a reply selected as the accepted answer. Similar to what Jive did, the answer could be featured at the top of the post, preventing visitors from having to scroll the entire thread to discover the answer to a question that was posted.
Ideally this would also have a Q&A 'Hub' similar to the other hubs in Linchpin, which would contain filters for things like status (Answered and Unanswered ), categories, labels, or "topics" (to follow suit with the Microblogs template), and a data range, for starters.
Macros for this could include a Timeline macro just like the one for Microblogs, which could have settings for Space, Topics, etc.