S/4 HANA will get soon the next release (avaiable for any customer of SAP). Some discussions can still be found. Here are some pages you should look at if you need information regarding S/4 HANA.
We can expect that in 2016 SAP will communicate the current future roadmap in context of “EHS applications” based on S/4 HANA. I hope that we will see an official blog here from SAP. If not: you as “user” of SAP EHS Management should really try to follow any discussion in any user group (e.g. DSAG, ASUG etc.).