For the first few years of the 350z, they offered a special color every year.
Brickyard (Maroon) 2003
Liquid Aluminum 2004
Ultra Yellow 2005
Then in 2006, I believe, several new colors were added (and some were discontinued). Seeing as the yellow was brought back (albeit under a different name) I wouldn't be surprised if they brought back Brickyard for all models. It's hard to judge what colors will be available in the future because, historically, Nissan has not been very consistent i.e. shying away from the "yearly special color".
One thing is for certain though, and that is that Nissan is always providing cool new colors for us to drool over
. I would personally like to see a gray that is a little darker than PG (closer to an anthracite color) and the return of an orange hue but preferably not solar orange.