Metallica updated code version 1.16 is now up on Stern's website for LE/Premium and Pro:
LE/Premium code: http://sternpinball.com/downloads/MTL_LE_english.zip
PRO code: http://sternpinball.com/downloads/MTL_PRO_english.zip
Here's what the 'read me' file says:
V1.16 - June 28, 2013
=====================
- Snake jaw no longer tries to re-fire during test if the device fails
to satisfy a request to get open/closed.
- Snake jaw hit was not lighting the snake icons on the playfield. This
has been corrected.
- Updated the mechanical snake to be in the correct state for the new
snake lock rule. The jaw is open when the lock is lit and closed when
the ball is locked or the lock is not available.
- Fixed a problem with the lamp effect for the combos that was causing
the lamps to be obscured.
- Added free play check to attract mode radio.
- Added snake lock feature. This is available during any multiball.
Completing the guitar pick targets during multiball lights the snake
for a timed ball lock. Shooting the snake the first time locks the
ball and awards add-a-ball. While the ball is locked, all playfield
scores are 2X. Completing the guitar pick targets again while the
ball is locked in the snake will reset the timer. Once the timer
expires, the ball is released from the lock and playfield scores go
back to 1X. The ball can be re-locked for 2X playfield scores by
completing the guitar pick targets and shooting the snake, but an
additional ball will not be put into play.
- Added coffin force field sound. Added art to coffin multiball super
jackpot display effect. Added coffin speech.
- Added attract mode flipper button speech.
- Added speech for coffin hurry-up.
- Added art for total screens (sparky multiball, fuel, metallica/justice,
snake, coffin, etc.)
- Added speech to the shoot again display effect.
- Added sounds for seek and destroy, ticket (redemption) award, coffin
hurry-up, cross super jackpot, coffin multiball, extra ball, and special.
- Added speech to "player up" effect.
- Lighting items (cross, snake, electric chair) will not light items for
shots that have already been completed (hurry-up collected). Lighting
neighboring (unlit) items (the snake is the only one who uses this) has
been changed to not spread out so much (it no longer skips over items
that are already lit, rather, it increases the count for those that are
already lit). Once a shot has been completed (hurry-up collected), the
number of items that are lit (available) is always 1. No matter how
high an item count (cross, snake, electric chair) is built up, shooting
the shot will only ever award one of each lit item (only the points
awarded and the starting hurry-up value are affected).
- Added effects for special lit and special.
- Added electric chair progress lamps. Fixed up electric chair progress
lamps in the explode/sweep lamp strings (#3 was missing).
- Added ticket (redemption) animation.
Louisville, KY
Ottawa, ON
but there is still a lot to do for me to be
I doubt we'll see video modes ever again. 
