Among the Jamaican English terms he uses, irie has apparently been a big hit, according to this story. I remember it from my 80s youth as a term of approval, expressing happiness and calm. Some have claimed that it is a state of extreme relaxation brought about by medicinal herbs, but I think that might just be a step too far.
Urban Dictionary defines it in several ways, the most voted for being "to be at total peace with your current state of being. The way you feel when you have no worries" which sounds fine to me. Wordnik has it defined as:
Positive emotions or feelings, or anything that is good. To be at total peace with one's current state of being. Phonetical representation of "all right".
This link about Rastafarian vocabulary on Wikipedia makes interesting reading too. And reading the bit about Armagideon/Gideon times makes me wonder if that is why George Osborne changed his name from Gideon (It's true: check the peerage website.). Is it all a conspiracy to hide the fact that with all his cuts we are really entering Gideon Times?
Can Rastamouse save us and make a bad ting good?
Edited to add: I've done a bit more about the grammar of Rastamouse over on the Teaching English Grammar in Schools blog.
p.s. thanks to Martina (aka Miss Osbourne - no relation to Gideon - for this top viewing tip)
p.p.s and apologies to my good friend Gideon "Gid" Calder for mocking a fine name.