Bear lottery winners must purchase their license by July 29, 2011. Unsold and any surplus licenses will then become available for one week to those that applied but were not selected in the lottery starting August 3, 2011 at 12:00PM. August 10, 2011 at 12:00PM any remaining unsold license will become available to anyone.
Back in the day I remember a lot of bear hunters just bought their license over the counter on their way up north. In the last few years - I would say since 2006 - bear hunting has sky rocketed as far as interest. It has become more difficult to buy a tag over the counter. They have even reduced the number of tags this year to promote higher success rate.
Remember that if you are planning to go with a guide you might be out of luck for the good ones. They might be full and you might be baiting for yourself. This is not such a bad deal. You might even enjoy the fruits of your labor a lot more.