The information that I have received from DFTW is slightly different for what has been posted above, but possibly because we are doing an Escape Wedding, so if you are a Wishes bride this probably won't apply to you.
Doreen from DFTW told me that our spot at SBP on January 22, 2009 at noon is guaranteed. However, we cannot sign a contract until Disney releases 2009 prices. Historically, according to Doreen, this will occur in May. As soon as the prices are released, we will be able to sign our contract.
HTH someone!
Amy