IM(H)O, it is absolutely vital that VisualEditor be enabled in talk namespaces. Otherwise newbies will be able to add stuff or remove content, but not to discuss it – which is guaranteed to cause edit-wars by the thousand. I don't know why the plan is to ignore talk namespaces; it seems very silly (and reckless) to me.
Topic on VisualEditor/Feedback
As is widely agreed, talk pages are horribly broken, and there is no proper way of helping users edit them in a way that "makes sense" because (a) they are not regular, and (b) they are not used in the exact same way between wikis. This would turn "editing talk pages" from what sounds like a simple request into a very expensive and slow thing to build.
A proper discussion system is already being built - Flow - and we will integrate the VisualEditor with that instead. It would be a huge waste of donor's money to spend a lot of effort trying to let users understand and edit talk pages when they will be replaced before we would be able to release such a tool.
When will Flow be released?
I don't know, but sooner than VisualEditor if we were to need to try to support editing talk pages as well. There's some information on the Flow project page.