Out of curiosity, I checked ticket availability for Atlantis’ STS-122 Decembe, 6th launch this morning. As usual, the launch transportation tickets are already sold out (I bet that happened again within a few minutes). However, there are still tickets available for viewing from the Kennedy Space Center main visitor complex. Depending on what is your main intension, this option may also be useful for you. You can read my previous post on launch viewing from the KSC main visitor complex to get an idea what awaits you.
I would also like to mention that there are still options to get launch viewing tickets for the NASA Causeway via third-party operators. Just be sure to use only NASA-appointed ones or you may run into trouble. I have written details in my post on “How to view the launch from closeby when no tickets are available?“.
Of course, you can also go to Titusville beaches. They are farther away from the launch site, but still offer a very unique view. If you would absolutely like to view the launch from the beginning, it is better to go to Titusville than to go to the main visitor complex (which, on the other hand, is better if you come with kids).