Technical info hasn't been released for the new JL, only a few spy shots and dealer presentation shots.
No ETA for tech info that I'm aware of, but I'm sure it will be posted in here when it's available.
He also run this page with lot of info about Grand Cherokee http://www.wjjeeps.com/jmenu.htm and it contains alot of pdf files from Jeep. I found a service bulletin in PDF for my Wrangler there, it was very helpfull