I have the 1DMKIIN and at 8.5 FPS it's a machine gun but that 10 FPS would be like a modern day gatling gun LOL

Only lenses that do not fit the D series are non L's anyhow I think.  Not sure if they make a L EF-S lens.

If you want to shoot landscape then get the 5D, if you want to shoot action then either look for a used N or buy the III when it comes out.  I am looking forward to the dust removal and some other things on that body and I'm not sure if I want to get it as soon as it comes out or in June sometime.  I'm a hobbyist but love my toys :)  I shoot mostly grade school sports but will be doing some H.S. this spring and maybe it will be time to make some money on the H.S. sports :)