There are some rumours regarding the all new 50 1.4 and 17-40L. It sounds plausible, since Sigma is now producing 50 1.4, which is quite a chunk of glass (77 mm filter) compared to Canon's 50 1.4 plastic light-weight standard lens. 17-40L should be replaced (in my opinion a long time ago) with a new, much sharper version. As we all know, its border sharpness is very poor and it has to be stopped down a couple of f stops to get good center sharpness especially at 17 mm. Canon really should put more effort in improving their EF UWA lenses in terms of image quality (they do make great EF-S UWA lenses, 10-22 for example). Rumours also say it's not going to have IS.