I can't believe I didn't find anything about it here. But I just found this on Nico Video:
tk21qsj4Ykk
Sorry the vid is out of sync, and it cuts off the last couple seconds.
As I understand, Yuriko Yamaguchi pulled a Vic Migogna and rearranged the infamous Nico Video Medley and added her own One Piece lyrics in a TEN MINUTE TRIBUTE SONG!! If I'm somehow mistaken, it's a DAMN GOOD imitator, and still a great song. She just did the song, not the meh AMV I got here. At least, if I'm understanding correctly
Well as Saiyajedi was able to point out, it's just a really spot on imitator. I actually found Luffy, Nami, Zoro, and Sanji "versions" though they don't sound nearly as on par.
I've also got the MP3 right here:
http://www.megaupload.com/?d=XUY7NAUA