Get a grill going good and hot, to about medium-high heat.
Lightly oil the poblano peppers and set them on the grill. Close the lid. Flip the poblanos a few times throughout as you grill, about 10 minutes or so, until the poblano skins are nicely charred. Remove from heat and cool. Set them into a sealable baggie and allow them to steam. Cool, then remove and peel off the skins. (Alternatively, you can either oven roast or flame roast the poblano peppers. See the post discussion.).
Slit the poblanos up the side and open. Scoop out the insides.
In a mixing bowl, combine cream cheese, cheddar cheese, garlic powder, chili powder, cumin, and salt and pepper. Mix well.
Stuff the cheese into the poblano peppers and set them back onto the grill over indirect heat. Close the lid and cook about 10 minutes to allow the cheeses to melt. Alternatively, you can bake the cream cheese stuffed poblano peppers for 10 minutes or so in an oven at 375 degrees.
Remove and set onto serving plates. Squeeze lime juice over them and garnish with chopped cilantro.