yeah there have been a lot more "CE" versions of downloadable games lately...
in most cases they include some kind of bonus in-game content, though more-often then not they're just an updated re-release.
For instance the "The Secret of Monkey Island Special Edition" is an XBLA game for Xbox 360, there is no non-Special Edition version, it's just a re-release of the PC classic with updated graphics.
We don't track them here since IMO CE collecting is all about the packaging and the included physical game artifacts... Downloads have none of that.
one interesting CE I do have in the database is Raiden IV for the Xbox 360
http://collectorsedition.org/game-db...diton-360-ntsc
the regular edition was a downloadable only game, but they released a physical "limited edition" on disc which included a 2nd disc with the game's soundtrack.