The original area music for the Imagination pavilion can still be heard in the bathrooms located on the side of the pavilion!
A very obscure reference to the original Journey into Imagination can be found in the current Journey into Imagination: With Figment queue. The plasma orbs from the Dreamport can be found on the shelves located halfway through the queue!
In Imageworks, you can still see the physical remnants of the turntable used in the first iteration of Journey into Imagination. You can even feel parts of the original track in the floor if your feet are sensitive enough!
It may be hard to hear with all the young imaginations running wild at Imageworks, but the original Journey into Imagination audio is used as a backing to all the instrument based “exhibits”. Without the vocals of course
In the "Disney & Pixar Short Film Festival" you can still find where Journey into Imagination and the Magic Eye Theater used to connect. It has since been blocked off, becoming a dead end.
A small section of one of the Dreamcatcher's used in the original Journey into Imagination can be found hanging inside MouseGear