This update is now mentioned on Samsung's website. It says it does the following:
Updates to support CMAS (mentioned earlier - disaster alert system)
Updates Android to 2.3.6
Fixes an Exchange remote wipe bug
Thank you so much! That was my issue as well, I had do not disturb enabled!
Alternatively, you can use the wireless tether app (I verified it works if rooted - http://code.google.com/p/android-wifi-tether/) but this method is definitely better