At NATPE yesterday, I spoke to Greg Clayman, EVP, Digital Distribution & Business Development, MTV, who overlooks all of MTVN’s mobile businesses. He moderated a panel on what’s working in mobile content, and I grabbed him after for this short 5 minute video interview (RSS readers will have to click through). He’s bullish on mobile video, which he thinks is going to take off this year. Then of course mobile advertising, and he’s seeing bigger campaign buys with MTVN (NYSE: VIA). Also, the surprising realities about the ringtones market…