It means something. It means the Celtics can win against a top team, but they knew that. It means they can win without Rondo, but they knew that, too.
However, I think it points to *how* they can win games. How they will *have* to play to win games against top teams. If they learn that lesson, take it to heart, that game could mean a lot. What it didn't tell us, or them, is if they can keep playing that style, giving that effort, game after game. Time will tell if they have finally heard Doc when he says "You can't win easy, you have to work hard, play hard, to win."
Turning point in the season? Who knows, but remember this team just played the Knicks to the last possession before losing, the Hawks to double overtime before losing...and in just as hard fought a game beat the Heat. That's a three game streak of effort, make it four, then five, then six...and maybe the team will have turned around.