It is as yet unclear whether that list is official in any capacity... though I have to say I like it because it coincides with many of my opinions (Puff/Ganon/DK lower, Yoshi/YL/Pika higher).
Someone in the topic posed the question of how he selected the "official" voters and I too would like to know this because some of the people on his list are both not-that-great-at-the-game and not-involved-in-the-scene-much-anymore so they seem kinda... odd.
Awesome! I did not like how the old tier lists had seven different (S, A, B, C, D, E and F) tiers. Since this one has been reduced to only four (S, A, B and F), it already looks better! It also gives a big SSB64 feeling with there only being four tiers. The description of each tier also helps more:
S- Viable Tier. All characters in this range are viable for competing. A- Semi-Viable Tier. These characters have been shown by their dedicated players to have the tools to compete, though it is apparent that they are slightly disadvantaged. B- Probably Not Viable Tier. Some players have done well with these characters in specific match-ups, but for the most part they aren't viable for winning tournaments. F- Just Leave Them Alone Tier. Its probably for the best.
This is something I can relate to because Mario is one of my best characters in the game. I know for a fact he's not the best (but far from the worst) which is why I use someone who is better at competing like Captain Falcon.
Overall, this is the first Melee tier list that I've seen updated ever since I started playing competitively (while still playing casual Pokeball only matches here and there) back in 2011 and it is so amazing being a part of it all.