It's not know where the original palm leaves ended up. If they remained in the material world, they couldn't survive till now due to a limited durability of a biological material. Some old manuscripts are kept at various institutions. See some links at the bottom: http://veda.harekrsna.cz/encyclopedia/vedas-purpose-origin.htm
Mbh states that he used to come from and return there. Details told by Madhvacarya are in Narayanacarya's Madhva Vijaya retold by Jayatirtha Caran P. in his book The Life and Legacy of Sripada Madhvacarya Bhagavatapada, ch. 3.
> Anybody know the story behind Veda Vyasa still somewhere in the Himalayas?
I read about once in either the Mahabharata or a Purana but will have to research again for the exact reference. As I recall, Vyasadevji is staying up in the Himalayas and will come down next to assist in the re-establish of the next Satya-yuga after Lord Kalki has performed his lila to usher in the next yuga.
