The odds that Philly finishes with a worse draft pick than Sacramento this year is rather low. It's a nice prize for Philly and all, but if the Kings are able to use it to sign Monta Ellis and/or Rondo, there's just very little way Philly has a chance to pass them this year. Next year, if that's when Philly finally decides it's time to win again, then maybe, although they just agreed with this trade to take on $9 million of dead money, so it's not clear that 2016 is their time either.
While I wanted Stauskas, I'm quite glad the Celtics didn't do this deal. I don't care about this year's salary space much, but I wouldn't at this point take on $9 million for next year.
Picks swaps happen after the lottery so the Kings don't have to finish worse than the Sixers for the Sixers to benefit. If a Kings ping pong ball wins the lottery (or top 3) in 2016 or 2017, the Sixers get their pick.
Derek Bodner point out that Sixers fans would have been happy to get Embiid and Stauskas from the 2014 draft. Now in addition to those 2 players, they also have Dario Saric, the Sixers own 2017 1st rounder back, the 2018 Kings pick (top 10 protected), the right to swap picks with the Kings in 2016 and 2017 and an additional 2nd rounder.