OctoPrint, OctoPi and the RPi3
Yes, I've seen the news too.
No, I don't have one yet, I hope that changes soon. In the meantime, based on the information I do have, this is what I expect:
Yes, OctoPrint should work just fine (at least I'd be very surprised if it didn't, since OctoPrint itself runs basically everywhere Python does run).
No, the current stable OctoPi 0.12 release doesn't
We need to build a new one for that based on the current raspbian lite release [...]
Apparently current 0.13 nightlies, which are still built against the Raspbian release from November, are working (Raspbian's release notes suggested otherwise), so use nightlies until a new stable release is published (no ETA yet, sorry).
Yes, the new Pi is slightly faster and clocks in at 300MHz more per core, but thanks to Python's so called global interpreter lock or GIL, OctoPrint can only use one of the four cores at the moment. That means that it's probably
rather unlikely you will notice significant speed ups when switching from a Pi2 to a Pi3, so if you are already on a Pi2, no need to throw it out of the window and/or to update immediately (especially due to the image situation). If you only have a Pi1 so far and were thinking about upgrading anyhow, I'd go for a Pi3 though after the initial rush calms down a bit.
Unsure: The on board Wi-Fi might support access point mode. If so that will get interesting in the future to make setting up your OctoPi image even easier than editing our octopi-network.txt file, but that is something further down the road.Edit
Updated to reflect that apparently current nightlies are compatible after all, contrary to what the Raspbian release notes indicate. Thanks +Mert G
for the heads up.