I'm about 20% into the special edition, and I'm loving it. The only problem I have with it is the "TM" after Melee Island, and Monkey Island. I first thought it was a joke, but they keep doing it. Did they have problems keeping that trademarked? Am I missing something from the first game?

This is my only experience with Monkey Island, so sorry if it's a reference to another LucasArts game.

He also says "Mighty Pirate™". I'm pretty sure it's a joke.

Maaaaaybe its just me, but I don't find it to be a particularly funny joke.

In Escape from Monkey Island "tm" is also used. In one part of the game, Guybrush is talking to some lawyers and one them says "nice use of the "TM'"

It's a total joke. It's also referenced in the latest Tales of Monkey Island.
"My name is GuyBrush Threepwood, mighty pirate" TM

Always happened throughout the Monkey Island series, it's a joke mate

It's a joke.

It's a classic recurring joke ;)