Artificial Intelligence: Good or Bad?

The basic premise that I am discussing here is whether or not it is a good idea to create humanoid robots with artificial intelligence. Why I think this may not be a good idea: if we create robots with our level of intelligence, yet with more strength and a body whose parts can be routinely replaced (allowing it to avoid death by natural causes), wouldn't they just dominate and/or replace us through natural selection? Could this theory apply to robotic creations?