actually downloaded the beta version 2018 a while back. however, been so busy i haven't installed it.
i think anyone with a login can download the beta, if you go to the sw website, login on the customer portal, then go to downloads. looks like "beta2" is now available. there is a legal agreement you have to comply with when it's installed.
they keep it pretty quiet, i did a forum search for "2018 beta" and the first thing i saw was a couple of NDA disclaimers. makes sense, i assume they want to save all "whats new" stuff for the official roll-out.