My ilvl bet for t15-t16 (yes half of t15 is known)
T15
NR : 522
N+ : 528
HC : 535
H+ : 541
SP : 548 (Ra'den)
T16 :
NR : 547/549
N+ : 553/555
HC : 560/562
H+ : 566/568 (Some future elite/heroic only possible boss!)
SP : 571/573
So we'll probably not end up even close to it.