This deck is composed of cheap mana acceleration, tutoring ability, and powerful creatures.
Its game plan is to use early mana to get ahead of the opponent and then use its tutoring ability to start a Vengevine chain, all the while beating with with undercosted creatures in the form of Myr Superion and Leatherback Baloth. It also plays some silver bullet creatures to gain flexibility and removal.
The biggest standout here is Birthing Pod, which is arguably the most powerful card in New Phyrexia. This deck can easily accelerate it out on turn 2, which is absurdly powerful. From there it can run up the curve to whatever creatures it likes. A mark of a good card is one that's good in every situation, and Birthing Pod fits the bill. It's just as great in the late game, and will often get you out of a bad position. It will also cement a victory when you are ahead. The only real drawback is the fact that it costs a card. This list makes up for that fact rather well. One, it plays cheap mana accelerants that lose their power as the game goes on anyways. Two, it can Recoup the card advantage with Vengevine. Finally, it plays some creatures that create card advantage, like Molten-Tail Masticore and the two 187 creatures. This deck is full of creatures and is unlikely to run out, so Birthing Pod should always have fodder. The only real issue would be drawing too many Birthing Pod, but this should rarely be a real problem, since additional Birthing Pod will have plenty of value in most situations.
Fauna Shaman supplements the Birthing Pod plan rather well, and has a very similar effect on the game at times. This gives the deck an additional amount of synergy and consistency. It's also a must-kill creature because of the Vengevine it Threatens to find.
Myr Superion is another New Phyrexia card that has caught my eye, and it fits perfectly here. First of all, this deck is full of mana creatures, so Myr Superion can be consistently cast very early in the game. Turn 1 Joraga Treespeaker can be leveled on turn 2 into Myr Superion. Another line is to cast a turn 1 Bird of Paradise or Llanowar Elf. This sets up turn 2 Lotus Cobra into a fetch land, which can cast Myr Superion. These are all options, but Birthing Pod makes the job much easier. Any 1 drop accelerant can be cashed in for a 5/6. Turn 1 Llanowar Elf into turn 2 Birthing Pod into Myr Superion is pretty hard for any deck to beat.
The 2 Moltensteel Dragon in this deck provide a powerful, cheap flier. These give the deck an added threat and angle of attack, since the rest of the creatures are ground pounders. It can be cast cheaply with Phyrexian mana or tutored out at the end of a Birthing Pod chain. The ability to be pumped gives the deck additional reach and a way to steal games.
The sideboard plays 4 Beast Within, which is one of my favorite New Phyrexia cards. It gives this monogreen deck, which doesn't have many ways to deal with problem permanents, like planeswalkers, a powerful and versatile solution. It's flexible and can be cast on anything. The 3/3 creature it creates pales in comparison to the huge creatures the deck plays so it won't put up much defense. Even something like destroying the opponents land on turn 2 or 3 should not be overlooked. One of the best uses will be to cast Beast Within on one of your own permanents. It's an instant speed 3/3 creature, which is excellent at ambushing attackers or planeswalkers, effectively countering removal, or simply putting the beat down on an opponent. I recommend just playing with it and the flexibility will soon become apparent.