I was unable to catch today's WWDC.

Until I am able to watch the reruns, will some kind soul tell me:
1) Was new hardware announced & estimated availability date(s)?
2) Was a new Car Play announced & when will it be downloadable?
3) Estimated release dates of the new macOS and iOS.
4) Musings and general impressions of what was revealed.

TIA!

No new hardware announcements of any sort. Car Play offering third party Navigation app compatibiity will be released with iOS 12 probably in the October/November 2018 time frame. See My Post on the WWDC for more information and a link to the WWDC video.

If you want CarPlay sooner you can register to become an iOS 12 public beta tester here. Be aware the early betas in particular, may have stability issues and are generally not recommended for "production" devices. In other words be aware that you are taking a risk when you use beta software and sometimes it can bite. Also be aware that beta updates are frequent, averaging one every two or three weeks and you want to keep up as features come and sometimes go from one beta t the next.

Many thanks, Joe.

And BTW, now that I have seen the WWDC, I found your comments/link a very well put summary.