The name of the song is ”Celebrate You” it was sung by Corbin Bleu.
You are correct, after the popularity of High School Musical, Corbin Bleu was given the pop version of the song to sing. However, the song Celebrate you was written by Robbie Nevil and Matthew Gerrard for the
Give a Day, Get a Day Promotion. In my opinion, the Corbin Bleu version of the song didn't pay it justice, there was no heart or passion in it, just pop and flash.
There was the original version, (sung by a gentleman can't remember his name) who says he only did a few chorus's, so, the song was incomplete) that was used for the original commercial. They also produced a country version for a different Disney album. However, the version everyone fell in love with is the parade version used in the youtube video I made above. It was never studio released, which is why no one can find it. I lucked onto it ten years ago on a music share site from a castmember that participated in the parade. Parade Castmembers were given a cd with the song to practice. This person saw everyone searching for it at the time and felt the song was too good not to share.
Trust me, I spent 6 month looking for THIS specific version to use for the family video. Close your eyes and play it back one more time,
this version is what excited everyone about coming to Walt Disney World.