Just to add.... with currently active (and those recently active) threads we'll try to leave
expiring redirects to help. These won't hang around for more than 2-3 days max though, just long enough to prevent threads dying due to lack of attention.
I've already moved one or two stuck threads to a more appropriate home; these can't be redirected but they're obvious.
In addition to what Xyro said, the Quick Links menu at the top of the page contains "All Your Posts" and "All Your Threads" links. Also, remember that you can add frequently-read forums to the "Favourite Forums" bar on the lhs of your screen for easy access.
This hasn't been done on a whim; AF needs a uniform structure that will make locating (and organising!) the rapidly-growing amount of information throughout the various forums easier. This sub-forum structure has been in use in several of the high-traffic device forums for several months and has worked well. Hopefully the same benefits will soon be seen here.