Currently if you don't discard a post/topic you can access it even after logging out, closing browser, etc. by clicking "New Topic" or "Reply" at the same category/topic again.
+1 for some kind of management therefor the user knows where drafts are saved (a private list within profile) and possibility to create multiple drafts would be nice.
Also a Draft-button that just removes the topic from taskbar and a list of drafts besides "New Topic" and "Reply" could prevent some confusion...
I'd basically say this is something for a plugin