[Update] New Pokémon Black and White creatures spotted in the wild

• Chiramii is a Normal-type Chinchilla that looks to be this generation's Rattata.  It knows a new move called Sweep Slap that can hit multiple times in one turn.
  
• The pink oddball (literally) Mun'na is a Psychic type that can force opponents to float off the ground.
  
• Plainly-labeled Gear is a Steel-type whose Gear Saucer attack hits multiple times per turn.
  
• Pigeon-like Mamepato makes use of the new "Pigeon Breast" ability that prevents its Defense stat from being lowered.
  
• Hihidaruma is the big, red intimidating Fire-type ape with an ability called Encourage.
  
• Electric-type horse Shimama knows the reckless Wild Volt attack that hurts both the opponent and itself.  
  
• Meguroko hangs out in the desert as a Ground/Dark-type crocodile that knows the useful Earthquake Spiral ability.  The ability raises Meguroko's Attack stat when it knocks out the opponent.
  

Black and White will also have the C Gear, a new gadget that will utilize the DS' wireless features in some way.  Most welcome of all is the ability to finally be able to have random matches over the internet but there's also a way to upload your save data online for some reason yet to be revealed.

Update: Cover legendaries Reshiram and Zekrom have been revealed to be Dragon/Fire and Dragon/Electric, respectively.  Players looking to add a Zorua to their line-up will look forward to transferring an event Celebi to their copy of Black or White.  Additional page scans also give a glimpse of the new Isshu region that the games will take place in.