I just installed and tried the Mac app today and wrote a post detailing my experience. Overall, I was really pleased. It was fast and clean. I ran into a couple snags with Media which I still haven't figured out but it's probably something I can solvesoon enough.

As a long time community member, I'm really excited to see what the next stage for WordPress will entail.

I do suspect there will still be confusion from novice users about the differences between WordPress.com, WordPress.org, and soon to come WordPress-Powered Applications but it's up to developers and the community-at-large to help define these differences and onboard new users appropriately.