And we have devices listed. TTYL I have work to do
You have to add the skill and Alexa can then control the scenes (but you have to say “turn on” rather than “open/close”).
Yeah I know it’s just a bit unnatural that I just end up using Siri
And you have to create two scenes, one for off and one for on no?
That was simple, just like any other C2C connection, enter Lutron credentials and add devices
Correct. That allows you to use the Lutron scheduler also (still trying to figure out open/close depending on the weather).
What’s the response time like?
Nearly instant… I’m pretty impressed
Funny, I don’t see the Lutron devices in the iPhone App.
They show in mine. Give it a bit or try closing the app and re-opening
They’re rolling out in waves. If you don’t have it now, you should have it pretty soon, at least if you’re in the US. I haven’t heard one way or the other if it’s going to be released for the UK at the same time.
Yup Androids are once again laughing at IPhone owners 
What will happen if I make the official connection even though I have all my dimmers set up with @njschwartz 's solution? Will I just see two of each dimmer?
If you add the same device twice you will indeed end up with two devices. I haven’t tried it since I have two Lutron hubs, but I think you may get some strange results. If you try let us know! 
It has nothing to do with android vs iOS. I have both and my smartthings app still shows just a “Lutron” section with no devices under it in both ios and android.
I had to reboot phone / restart ST app before they showed.
I have an android and I can see the header for Lutron but no devices under the header. I have rebooted and restarted the app.
It can take up to 24 hours for the Marketplace entries to roll out to everyone. Hang in there!
Lutron devices finally populated on my iphone. Added a switch, provided Lutron credentials and it discovered the shades! But, looks like Alexa identified them as a dimmable switch so will still have to say “on” rather than “open”.