SCG's "decks to beat" for Vintage are currenty as follows...
4C Control: I don't think this can get a second turn kill at all. It is better known for Mana Draining into Exalted Angel or Skeletal Scrying. It's not a fast deck by any stretch of the imagination.
7/10 Split: This deck tries to get board control by Welding in Sundering Titan to take out opposing dual lands. It has the nasty capability of getting Memory Jar out quickly and going broken, but it's not going for second turn kills.
Affinity: This is an aggro deck, and fast enough. Still, I would say its clock runs a bit slower than second turn most games.
Bazaar Madness: Another fast aggro deck. Still, I think third turn is more realistic for such aggro decks barring godlike hands.
Belcher: Obviously this is the perfect example of what Mythosx is talking about. It also loses to even small quantities of disruption. To my knowledge, this deck has never really reached tier 1.
Control Slavery: This deck attempts to lock the opponent down with Goblin Welder/Mindslaver. This makes for longer games.
Food Chain Goblins: If it goes crazy with Goblin Recruiter and Food Chain, then it does have a fast kill. Even without them, it can pull of some fast beats. Second turn would be a bit optimistic though...
GAT: I suppose if things go perfectly for it, Yawgmoth's Will can get a relatively fast kill. Normally things are a lot slower.
Hulk Smash: Once again, this deck focuses on keeping control, and fast kills are very rare.
Long Death: A very fast combo deck. It also happens to be very difficult to pilot. While the speed is adequate, it isn't enough to be dominant.
Mono Blue: This deck uses Ophidian. It is not fast.
Stacker: I'm not sure what the fastest kill for this deck would be, but first turn Juggernaut, second turn Juggernaut isn't going to be a second turn kill...
Tools 'n Tubbies: Not particularly fast.
TPS: It is good not because it has more speed than other combo decks, but because it is more resilient.
Trinistax: Prison decks aren't typically fast.
U/G Madness (Budget!): I don't know why this would be on the list. I doubt it's as fast as the other Madness deck.
U/R Fish: It attacks with Mishra's Factory and Spiketail Hatchling and stuff. Not fast.
Workshop Slavery: Another prison deck that attempts to take all of your turns for you. It is slow.
As for the format Mr. Paper Shead is talking about, I am not sure what counts as "passed recently."
MD5 block comes to mind as a format where Wizards basically built the decks for players to use (as the synergies were so blatantly obvious). Then again, that pretty well describes what has been going on for the last four blocks (but without so much brokenness before Mirrodin). It looks like it may finally have been halted in this latest block, which is good.