Something super dodgy just happened, I was in the Kitchen (at work) when aj came in and said "I heard about the bad news" so I said "whats that" and he said "that your leaving" so I said "what the hell are you talking about" and he said "well thats what everyone else says".

Hmmmmmmmmmmm

Gonna have to have a word with my boss or should I have a word with everyone else?

This is fuct.

I probably would ask my boss if I'm going to get the sack. I wouldn't be able to work... not knowing the truth. But I presume that its some stupid rumor... like Chinese whispers. It started off by you saying " I'm leaving for lunch" and from there on it escalated to " I'm leaving for good" ... Nothing to worry about.

Personally I'd pick up the nearest assault rifle and show them what rumours do to people...

But seriously, I'd have a word with your boss. Make sure there's no substance to the rumour, then tell your cow-workers that you did not find their little joke funny...