Yeah, comparing this to Hellgate is over the top. The only real outstanding issue is networking, and that's hardly gameplay based.
Now going back on topic, I'd like to see a map control defensive hero. Something that can summon towers, or create patches that are dangerous to cross.
Even though we already have a "frost" ability using Demigod, another might be nice. I was thinking something like a frost elemental, he could drop ice shards that slowly freeze the area around them. The frozen areas would buff allies and debuff enemies, maybe allow him access to unique abilities or change his current ones while he's in the frozen spots. Upon the shards being destroyed, the frozen areas would slowly melt. These would give him map control, slowing people who cross through particular areas and even making ice walls to slow down advances until they are destroyed.
He could be a General and his unique minion the shards even, despite them not moving.