QFT. Sengir Vampire ain't what he used to be. (Neither is his counterpart, Serra Angel - look up Baneslayer Angel for a crash course in what five mana will get you for a white creature these days.)

My advice? Play heavy blue control. Counterspells are pretty much the only thing that have gotten weaker instead of stronger lately, and they'll give you a way to deal with his planeswalkers (which, I agree, are pretty overpowered).