The most recent announcement about OF 2's arrival can be found in this thread:
http://forums.omnigroup.com/showthread.php?t=16783
Omni typically charges about 1/3 of the new price to upgrade to the latest version from any previous version, so you are probably looking at something in the neighborhood of $30 to upgrade. There's a 30-day return policy, which effectively gives you a free upgrade if you happen to buy right before it ships.