I spent about an hour with the game over two days, and here are the facts:
B button grapples, and LT+B does a strong grapple (slower grab obviously).
Once in a grapple state you can press X or A for a front grapple, B for a back grapple, or Y for a hammer throw.
All 4 buttons show up under each wrestler and kinda like Tecmo Bowl, if your opponent guesses which move you're going to do, he counters it.
The only time I saw that your opponent couldn't counter was after a successful parry (more on that in a minute) or a back grab.
RT is the block button and depending on your "luck" stat it will sometimes turn into a parry (the glowing orange hand from the gamespot article). It doesn't seem to be timing based.
X button does quick strikes and 3 hit combo strings. A button is your heavy strike (big boot, dropkick, etc).
LT runs, but you can't do any kind of running strike/clothesline. If you run toward someone and hit x/a you'll just stop running and do your standing strike. The only way to execute a running grapple is to first run toward the ropes, and then run off the ropes toward your opponent. The problem with this is that it seems pretty hard to line up exactly with your opponent and hit them with it, especially since they can easily move in any direction and "groggy" states seem extremely rare. Also, a quick strike will always beat a running attack.
You get one downed attack using the x button. It might be a stomp, or a submission (even though there aren't submission wins in this game that I could find) or maybe a spanking. if it's one of those grapple type moves you will kick the opponent until they spin into the right position and then have to hit x again to execute the move.
B at a downed opponent will kick your opponent to a standing position but they'll be able to immediately attack, and probably will by mashing x.
If you hammer throw to the ropes you can do a rope rebound grapple. If you hammer throw to the corner they'll just bounce out of the corner. No corner grapples.
RB does top rope moves, and planchas to the floor. Y button climbs ropes or leaves the ring. I don't think there are any foreign objects.
The 3 meters are heart, spirit, and stamina. The stamina meter decreases a set amount for each move you execute, but doesn't seem to really matter in the early going as most moves that are initially unlocked have a very small stamina requirement. If your stamina gets too low, your wrestler will start to sweat, and if you just stoop attacking for a minute the meter will refill. I don't know if you are more likely to get pinned with low stamina, and there is no breathe button.
Life meter is exactly what you think it is, and spirit meter fills when taunting (Left, right, or down on the d-pad) and doing moves. More variety = more spirit. When it is full press up on the dpad for finisher taunt (which can be interrupted, so make sure your opponents are down) and then you are in finisher state. Any attack will knock you out of finisher state though. If you successfully grapple whilst in finisher state you will go into the finisher animation. If it's a tag team match you can't do your normal finisher, because it will always be a tag team finisher.
You get an avatar award ( a lucha mask) for completing all the tutorials (or maybe it was all of the tier 1 campaign, I can't really remember).
Bottom line = 4 front grapples (2 weak, 2 strong), 2 back grapples, 1 light strike, 1 heavy strike, 1 downed move, 1 top rope move, 1 outside dive, 1 rope rebound move, 1 finisher, 1 tag team finisher, 3 taunts, 1 finisher taunt.
I'm sure I'm forgetting some other important info, but does anyone have any questions I might be able to answer?