I made a cool (but old) discovery.
Two Mother 3 albums, Mother 3i (tracks and medleys arranged), and Mother 3+ (more rock-like versions; credited to "DCMC"), are on sale on iTunes. I knew about the existence of these two albums (particularly 3+), but didn't know this was how they were released. It's kind of hilarious. "Hey, here's some awesome Mother 3 music…. OOOPS NO GAME TO GO WITH IT SORRY FAGS HA HA HA."
But this was the cooler part; I DLed Mother 3i, and listened to a track titled "From Utopia." It starts out with an awesome arranged version of the New Pork City theme, and then fades into an arrange of King P/Porky's Theme.
And the arrangement for that tune is the EXACT same one being used in Brawl.
That just took me off guard. I was pretty fucking amazed.