RE: What cool new Pokemon/evolution do you want to see in the 6th generation?
I've never seen the lion fish in Seadra, but now I kind of do, now that you've mentioned it.
Here's a few ideas and concepts for new Pokemon.
Glow Worm Pokemon - Obviously a bug type. GameFreak could play around with this and make it breathe fire or ice out of it's mouth where it would, IRL produce string. I also could easily imagine an Electric/Bug typing coming out of a glow worm-based Pokemon. If GameFreak actually makes the "Light" type, I could see that happening as well. I could see it using moves such as: Crunch, Thunder Fang, String Shot, Electroweb, and Bug Bite. Ability: Clear Body or Overcoat
Squid Pokemon - Not a whole lot of suggestions for this. The obvious choice would be a Poison/Water type. Or maybe a lava-dwelling terrifying kraken. Possible Moves: Crunch, Wrap, Constrict, Smokescreen, Octazooka, Peck, [I could imagine it having a beak, possibly.] or Bind. Ability: Poison Point or Clear Body
Mosquito Pokemon - Could be a Bug/Poison or a Bug/Flying. Even a Bug/Dark. Some say that Mosquitos are the most dangerous organism from the Animal Kingdom. This blood-sucking midge-like fly could be a very annoying Pokemon to deal with in battle, even if GF gives it low stats. It could moves such as: Bug Bite, Gust [If it has strong wings.] Wing Attack, Bite, Crunch etc. Ability: Swarm or Compound Eyes
Midge Pokemon - A midge is also a blood-sucker. It could be a pre/evolution to the Mosquito Pokemon I was talking about above. Even maybe a counterpart to it. It could use various moves like: Bite, Bug Bite, Poison Sting, [Even though I don't think it's venomous IRL, I could see it.] and Taunt. It's evolution could maybe learn the Elemental 'Fangs or Crunch. Ability: Swarm or Compound Eyes
Gerbil Pokemon - I don't see why it couldn't be the traditional Normal type-rodent Pokemon that evolves at level 20. It's moves could be something like this: Bite, Crunch, Scratch, Vicegrip, Tail Whip, Dig, Defense Curl, etc. Ability: Pick Up
These are just suggestions. I don't want to spark any arguments or anyone to hate on me. .-.