It's Kansai-ben. More exactly sayting, some-part-of-Osaka-ben. In my view, however, because many comedians are from Osaka area and use Osaka-ben as their identity on TV, many people(especially youngsters) do understand and use it nowadays as slang.

I *think* it is just slang.... (But, I'm not well acquainted with Kansai-ben....) Here's a site that has different casual/slang forms: http://www.guidetojapanese.org/casual.html ~Megumi