First up, if you downloaded Super Turrican, you might've noticed the operations guide has a whole list of enemy sprites - Including a few not in the game. These are from a never released original version of the game that Factor 5 has dubbed "Super Turrican - Director's Cut". Aside from some extra enemies and weapons, it had some extra levels. The game was actually practically completed in this form, but Nintendo told Factor 5 to put the game on the smallest possible SNES cartridge, so they had to cut and edit some of it.
Turrican (The user) says that the Director's Cut still exists somewhere, and also hints at a possible release for it with two seperate quotes:
So, that Super Turrican - Director's Cut is certainly not lost. Just slightly delayed
Super Turrican - Director's Cut is safe. Not only on a floppy disk. Releasing it in some shape or form is another story. Let's get Super Turrican 2 out first, shall we?
So, could we be seeing the VC's first never before released game sometime soon? Only time will tell!
Another member of the forum also asked Turrican if the Commodore 64 Turrican games will be coming to Europe sometime soon - At this point, they're not.
The NeoGAF topic in question can be found here (Turrican has only posted on the very last two pages).