So I originally architected Concrete CMS in a nice little bar in SE Portland to deal with an adCouncil gig we had with too many stakeholders and not enough time. That was many years ago, and since the early days my dear friend and comrade Andrew Embler has taken the loose direction outlined in my sketchbook of "blocks and collections" and made it work on fixed budgets for demanding clients. Concrete has had some really compelling concepts since those early days, but like any box of tools you use hard – there's some idiosyncrasies that drive you up the wall. Being the guy finally responsible for training clients, and getting content into working sites that make sense – I've been looking forward to getting my hands on the complete re-haul concrete5 for some time. I've peered over shoulders a lot, but today was the first time I got to play with it on a site I need to deal with.
Today I took the 188.8.131.52.a1 release on sourceforge and installed it where concrete5.org is going to live and started building out the site. All I can say is: "oh yes." Of course, I'm already filling up notepads with new to-do's, but the UI and experience is simply a joy. The in-context editing that has always defined the ease of use in concrete is finally as seamless as it was dreamed to be. No popups, all overlays, just like you're opening up the static page you've viewing and changing what's on it as if it were a piece of paper.
The biggest challenge in front of us right now, I think, is what the default skin looks like. Right now its just our old corporate site. We can go vanilla, we can come up with a dozen simple templates like Wordpress.. So much of adoption is how powerful and on target it feels at a glance, we gotta make sure everyone "gets it" within minutes or seconds of installing it.