The only possible attack here is that over the next several months MP will explicitly reject blocks from nodes advertising they are 70010 protocol. For this to have any material effect though, he would need >50% of the current network hashing power to also explicitly reject those blocks, so that people running XT are disincentivised to continue doing so.
I have joined btc way too late to have a clear picture of MP's "arsenal" consistency, but it's not the first time that I heard a respectable member of the community to refer to his disruptive potential in a serious manner. To make a long story short, is he really so powerful?
absolutely not.
i've never heard of him influencing anything except for the bunch of Cripplecoiner's around here who seem to idolize him. or maybe he's a father figure.
there'e probably plenty of Bitcoiner's who have more coin than him, if that is even a measure at all of power, which i doubt.