For those who are contemplating Sony's a55, this fast wide-angel lens is a good alternative to the kit lens provided that you already have other A-mount lenses on hand: Tokina AT-X 116 PRO DX AF 11-16mm f/2.8 (*Mount available for Sony A-mount)
The lens is not cheap but absolutely worthy of every penny you spent on it. Note the SD on the lens body. It features 2 SD optical glasses. Go here for the technical bit. Another good news is that the lens can be used on a full-frame camera at f16 where shaded angels will clear up. Go here for the illustration.