I don't really have too much say in this issue, as I am not totally aware of the facts, but to those who don't fully know what a GMO is or how it's made, its really not the evil, terrible things people make it out to be. The process is extremely easy and it doesn't require mutation or any other crazy thing like that, which in my experience a lot of people seem to think.
The research I do in college involves GMO organisms. Last semester we inserted fluorescent jelly fish genes into bacteria, and as a result, the bacteria would glow under a light. They have also been able to do this for other animals as well, like cats, and mice, and even cows and goats.
I think Monsanto is scary, not because of the GMOs (personally I think this is an extremely interesting and useful field!) but because they are looking to monopolize the seed industry. This will reduce choices for farmers who may want to choose between natural and GMO. It will also raise the cost of natural seeds, as monsanto begins to flood the market.