What's the deal with the 14mm?

Should I buy this lens? It's so much cheaper than the Oly 12mm (not to mention smaller and lighter), and I keep reading mixed reviews: some say the Oly is ten times better; some say there is little difference.

Also - why do I keep seeing this lens on ebay for like $190? A bunch of ebay sellers have them listed with no retail box, stating they were separated from a Lumix camera kit. Is this legit, or IF I buy one, should I buy through a reputable dealer and pay $125 more?

And when in the #$%^&* is Oly or Pany going to come out with a wide, weather-sealed prime?