You will probably hear a lot of "aboot" and "eh?" than you would than in any other part of the country.
LOL... Every town seems to have its own language, so when you can understand a townie (someone from town - aka St. John's) the rest will take a little time to figure out what they are saying.
Have some fun with the "Newfies" while you are there for business. If you get into a conversation with the locals, they tend to be long-winded and tell really great stories. (At least every Newfie I've ever met did!)
The ability to tell stories is a skill all newfies are born with. Being long winded is just knowing that it takes time to tell the story over and over!!!
And if you get a hook up for a kitchen party, do not miss out!
I've only been there once (proposed to my wife in a small town about 1 hour from St. John's - that itself is a long story), but I wouldn't hestiate to go back again. Though I'd do it in August. This time of the year you can start to feel the winter coming (about 50f this time of year) and thats too damn cold for me.
Have a good trip. If you get stuck somewhere's, offer to by a round of drinks and you'll have friends for life.
Kris