From the standpoint of a developer of health IT, it does not really add any new requirements, like with a MU Stage X rule. The proposed rule just states that CEHRT is required but does not expand on the definition CMS already gave with Meaningful Use Stage 3 (and also proposed for MIPS). However, it explicitly requires use of CEHRT in attestation for this program which will likely expand the use/need for EHRs, especially areas like post-acute care which have not had the same level of adoption of health IT compared to inpatient settings,
Toward the end of August, CMS issued a Final Rule updating its prospective payment system (PPS) for for services provided by long-term care hospitals (LTCH). (I won't even try to quote the nearly 100-word-named full rule name here). This rule largely deals with payment rates with the details of various adjustments and reductions you would find in such a document.
From the standpoint of a developer of health IT, this is not a rule that largely affects you. It does reiterate the current CMS policy of using 2015 Edition CEHRT by CY 2018. Also, it reiterates the IPPS/LTCH PPS (goodness CMS loves its acronyms) guidance on aligning the eCQM certification with CEHRT and using QRDA I (no more acronyms!).