Pinball news have a little more detail http://www.pinballnews.com/games/metallica/index.html
first thing I looked for was the playfield artwork - and it is illustrated. Looks excellent - a bit similar to Monster Bash in a few ways, but I like it a lot. No photoshopped images which is a big move forward. The Cross is used throughout the game, which is interesting. As a band, I cannot recall any religious connotations. I'd expect to see a Black Sabbath pinball with the Crucifix all over it.
Straight off the bat, the artwork looks very cool. The layout looks promising. Big tick for Stern on "Day 1"