Had a few hours today, so did basic Hellos for the trinket, then 12 led ring running off usb power, then both rings running off external 5v. Initially forgot to connect ground to trinket and got unpredictable results rom the chained rings, once I'd done that, all is good.
They are super bright, like everyone says. Next tasks are to work out how to lower brightness, power trinket from same supply (currently usb), play with some ideas for displaying time and get the RTC hooked up.
Another mode to think about - fake TV holiday mode, for when you are away, a few hours of random colours to simulate a TV set.