My Guess:
PC - Yes
360/PS3 - Probably not.
If any of you have ever messed around with the Cryengine 2: Sandbox 2, you know how many features that program packs. I doubt that they would be able to optomise the interface and streamline the functions enough for a Joystick/Button layout. There's just too many functions. If you have looked at some of the screenshots for Sandbox 3, it has the same layout and interface, just more functions. (Making it even harder to port to consoles.) However, the fact that they have released Screenshots and videos of the Sandbox 3 editor in action on major videos makes me assume that the PC gamers will definitely see the Sandbox 3 editor on PC. I could be wrong, but I doubt Crytek would want to leave PC gamers in the dark without an editor, when some pretty fantastic user-made maps came out of it on Crysis 1/Wars (all DLC-Related cynicism aside).

i clearly see xbox and ps3 at the bottom

http://i.min.us/il4Rmy.PNG

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
DUDE stop posting huge pics! It messes up posting.

@ this.
Yea, that says 'PS3 not connected'. Basically it means you (or whoever took this pic) didnt have a PS3 (or 360 for that matter) dev console hooked up to the computer to use live create.

@ presenT momenT
Its completely different. When you're editing the map the ENTIRE THING needs to be loaded into ram. Thats just how the engine works I guess. Yes, the consoles can run the game of course, but this is because they stream it off the hard drive. The fact that it works is impressive, but this late in the game Crytek would literally need to re-build the engine code in order to work.

Yes, removing the fancy stuff would drop memory usage, but just opening a blank map uses more RAM than a console has. However, loading it in the actual game uses far less. Just for example, the image posted above of the editor is using 885mb of ram - more than 3x that of either console has, let alone is available. In-game they stream bits of it (as I said before) and this is basically what makes the entire game possible. As it is, getting the game to run on consoles at all is hard, as (i've found out through checking the 360 and ps3 config files - they were in the 360 demo for some reason) they are already have dropped every single memory-intensive things to very low settings.

http://i.min.us/ij1KDQ.PNG
100 MB, big deal.