"is he planning a new DAC?"
That was the first thing I thought when I saw his resignation. That's a very exciting notion, IMO.
I was sadly completely out of the loop when Dan left Bitshares and started Steem, but much later I recall seeing a screenshot of the bitsharestalk.org forum where dan gave everybody willing to listen a huge tip: he said "check out this weird stealthy steem thing. It's legit." I wasn't around, and if I had been, I don't know if I would have had the smarts to follow his tip - but anybody who did could have made a fair amount of money.
Will he start his new DAC as stealthily as he did Steem? If so, we need to keep vigilant and make sure not to miss it.