The Canon EF 24-70mm f/2.8 L USM is on sale for $1250 at Downtown Camera. Seriously considering getting it (but having second thoughts after only shooting about 100 shots with the 50mm and that the 24-70 weighs nearly a kilogram).
Need to shoot some more downtown landscapes with the 50mm to see its limitations. Maybe I'll just get a 24mm prime used by the backstage photographers featured on Behind the Lens.