Pointed Discussion

Notice the "each" in the land's wording.
This might make this card especially useful if you run it in a deck that gets out many creatures at once, which will most often be a deck running tokens.
Snake Basket for example is such a card. Given that you have seven lands, you could then either decide to put seven 1/1 snakes into play, or only four of them and make them 2/2.

Why? This land isnt legendary :) Run them four at once with something that will allow you to make a lot of creatures for small cost, as Myojin of Life Web or something like that and you will have army that will crush any ground deck for nearly none mana.

I can only imagine this with tokens. Aggro Simic has better stuff for the mana, and Control doesn't pull enough creatures for this to shine.

possibly better than Oran-Rief, the Vastwood

Yes, this land works greatly with tokens. Despite the color restriction, Heart of Progress belongs to Simic and the guild utilizes +1/+1 counters like no others. Try Patagia Viper :)

EDIT: Also, this card puts +1/+1 on creatures you don't control as well, so it works with multi-player teammates and, if you're desperate enough, put counters on opponent's creature to control them with Cytoplast Manipulator.

The best friend of any creature with flash. Opponent activates this, boom. Thanks for the counter, BRO.

Experiment Kraj

An interesting interaction with the new mechanics coming up in Dark Ascension. You played a creature with Undying? Cool, I'll put a +1/+1 counter on that...

Good way to get doubling shenanigans started up in my Vorel of the Hull Clade EDH.