nah, Sylvanas is best in control decks like Control Warrior or Handlock
specifically Handlock because of Shadowflame combo being able to immediately activate the Deathrattle effect while clearing the board

Handlock is the one control deck I want to play, but it's one of the most expensive to craft
also, the Dreamhack Grand Prix is all this week if anyone is into that: http://www.twitch.tv/dreamhackhs