Un the book "Beatles Gear" (copyright 2002) by Andy Babiuk he says it was recently sold at auction. It doesn't say to whom.
This is also mentioned in the link I provided. It appears there is some controversy on the authenticity of the Premier kit currently owned by Hard Rock International. The last report of it's location was at the Hard Rock Cafe in NYC on Broadway. The article's author states the swirl pattern on the rack tom runs in the wrong direction from all of the actual photos of Ringo sitting behind his Premier kit. After this little detail was brought to their attention, the Hard Rock has stopped responding to the author's inquiries.
With that, I believe the kit is still out there somewhere. Just like the article mentions, it could be in someone's basement/closet/garage or worse, in a landfill. The last reported possible location was Australia. Drum City sold it to a business man vacationing in the UK and had it shipped back to his home.
-Tim