I dunno if you can build you own levels with the editor too
You certainly can build ( and share ) your own levels, but there is no editor, that's the great thing. At any time, you can just stop and start creating or modifying the level. The editor is integrated fully into the game, apparently.
I consider myself pretty darn cynical and unimpressed with so much of the "new cool things" in video games, but LBP blew me away, and this is now genuinely above MGS4 and FFXIII on my looking-forward-to list.