Release notes are published with every software release, accessible via the Downloads section on the InfoSight portal. For reference, the release notes for v1.4.7 (GA) are at Nimble InfoSight v1.4.7 release notes
Your Nimble SE/reseller SE should be able to keep you notified with any impending/published software versions, particularly if you're waiting for a particular feature. I do think a NimbleConnect post would be worthwhile when a new software version is released, makes it public knowledge!
Having some threads/firmware announcements on the forum is a great idea, especially for new fixes or enhancements that have been made for the product. For example, the CS400 series arrays have had a considerable performance enhancement in the new 1.4.7 firmware release, but there's no mention of it here at the moment. Good suggestion guys.
The only reason I believe we don't post firmware update notices on the forum today is that Support run a phased rollout of firmware updates to various batches of installed systems (ranging from currently installed firmware versions, array generations and amount of additional disk shelves on said arrays) and enable the firmware release for batches at a time. So I guess Support may not be too keen as it may spike incoming queries asking why the firmware is not visible on the array to be downloaded.