It is interesting I have noticed, maybe it is uncommon but I just started paying more attention on the run to the playoffs/playoffs and there have been 2 times that runner was called safe because second baseman left the bag early on double play...but this is why they do that...so I wonder if umps play into this forcing guys to stay closer due to those calls on these types of plays to be sure of the out?

Tough play by Scutaro to stay in there and attempt to get some ooomph on his relay, and he paid the price for it.

I listened 'live' on radio and it wasn't until later that I saw the replay. I was listening to SF radio announcers (Jon Miller makes the game so easy to listen to!), and they described it as a hard aggressive slide. I don't recall too much discussion of whether it was illegal, just more concern for Scutaro.

Upon review of the replay, yes, he landed on top of the bag with his slide and then willfully carried himself well past the bag to collide with Scutaro. I don't think Holliday's hand could have reached the bag from where he ended up (after Scutaro's left leg and body brought his momentum to a stop).

This is why second basemen used to jump to make their relay throw (not just moving towards the pitcher's mound and waving their left foot in the vicinity of the bag as we often see these days).

I also don't think Scutaro realized how just how close Holliday was when he chose to stay planted to the ground to make that throw.

One aspect of this game that was completely lost was the Carpenter error on Crawford's chopper. Crawford was very obviously running inside the diamond.
http://mlb.mlb.com/news/article.jsp?ymd=20121015&content_id=39842154&vkey=news_sf&c_id=sf&partnerId=rss_sf
The throw did not hit him and Carpenter's throw was well wide, but on that type of bunt, the runner's position has a huge effect on the fielder's throw. Belt would've still scored from third either way, but Vogelsong would've been up with 2 outs, likely ending the inning. Instead, Vogelsong sacrificed, Pagan walked, and then Scutaro drove 3 runs in. If you take those 3 runs away and the 2 runs from scoring after the blown call, this game has a dramatically different tilt.

The Holliday cross body block might well have been illegal in football because it was blindside and at the knees, a sure way to break legs, dislocate hips and ruins acls. The runner at first should have been called out by the second base umpire because it was clearly and unambiguously an intentional attempt to hinder the second baseman from making the throw. The rule says

Rule 7.08(b) Comment: A runner who is adjudged to have hindered a fielder who is attempting to make a play on a batted ball is out whether it was intentional or not.
If, however, the runner has contact with a legally occupied base when he hinders the fielder, he shall not be called out unless, in the umpire’s judgment, such hindrance, whether it occurs on fair or foul territory, is intentional. If the umpire declares the hindrance intentional, the following penalty shall apply: With less than two out, the umpire shall declare both the runner and batter out. With two out, the umpire shall declare the batter out.

The old saw about " well he could touch the base' has no basis if the move is intentional. If the umpires don't start calling and forcing runners to slide towards the base instead of sliding at the second baseman/shortstop and reaching sideways or backwards to touch the base, someone is going to get seriously injured.

Holliday was extremely lucky this was a post season game and that an old school pitcher wasn't on the hill. He might well have a really sore rib cage and he would have earned it.

Holliday's slide was Bush League