Just wanted to give a quick update that I installed a newer Beta Build on my PFSense box (used 2.1 Beta built on built on Tue Feb 12 08:58:22 EST 2013).
That fixed my IPv6 issues.
On a related note (at least I think it is), I was making some posts in the Speed increase thread showing that my upload was going nuts (speedtest.net was reporting upload values anywhere between 15 MB/s all the way up to 40 MB/s). Once I installed the newer version of PFSense, those issues seem to have been resolved as well.
I did not actually try a speedtest directly connected to my modem to fully verify this, but since last night, my speed tests have been showing exactly what they should be (25/4 as I have powerboost).