Even after a redesign I wouldn't expect the MBP to be much lighter or smaller, as some suggest.
The MacBook Pro is just that ... a Pro. It is not a top-priority to make it light and mobile - there's already a product for that! The Air. It's a priority to make the Pro top-of-the-line. A fast processor, good discrete gfx, large hard disk or SSD ... they will most likely just speed bump, so they can keep calling this macbook top-of-the-line.
The MacBook Pro is just that ... a Pro. It is not a top-priority to make it light and mobile - there's already a product for that! The Air. It's a priority to make the Pro top-of-the-line. A fast processor, good discrete gfx, large hard disk or SSD ... they will most likely just speed bump, so they can keep calling this macbook top-of-the-line.