I just read Syl Arena ‘s Canon Speedlite Wishlist. It’s a very interesting and detailed list of things that could be improved in Canon’s Speedlite flash system.
I agree with many points there. One thing I would add is to build a makro flash like the Twin Lite MT-24EX without the annoying cables. The flash is a wonderful tool but the cables often get in the way. The Nikon system does work without cables.
As so often in the last years it took Nikon a few years longer to offer something similar as Canon but when they finally made it, they got it 100% right and in that case better than Canon.