I guess the obvious question would be why. There are so few posts in the Learning Latin Forum right now. Why not just post threads there? Many of textkit's regulars come here using the "new posts" link, so they'll see the posts regardless of the forum used, and the others, who scan by forum, will just have to add one more forum to their search pattern. I actually think the time has come to consider dissolving the current "book-based" system anyway. The M&F forum has 13 threads with contributions in 2010, Wheelock's has had 10, and D'Ooge has had 7. It just seems an antiquated way of doing things.
What I would suggest is making a thread with links to all the LL posts, sorted by chapter, and keeping it up to date. I made one like that for Pharr (shame on me for not doing a better job keeping it up to date):viewtopic.php?f=22&t=7079
It's now a sticky. Anyone looking for discussions about a particular chapter will see them all linked together, but those who come by regularly looking for new stuff wouldn't need to add one more forum to their search pattern.
The problem I found is that even with a dedicated forum, like Pharr has, old posts just get lost and forgotten about because the forum sorts them by date of last post. The search function doesn't work well if you just want to see what other people are saying about a particular chapter, because there is no universal term to search for (some people put chapter 11, some put XI, some write out eleven and some just say page 38 or whatever. What you really need a central location that will keep all the LL posts sorted in a meaningful way, and then it won't matter what forum they're posted to.