The talk coming out of this week's episode of Monday Night Raw was that WWE retired the World Heavyweight Championship belt when John Cena handed it to Ric Flair on his way out for the main event. You can watch at the 3:20 mark at this link or embedded below:
While I can't confirm this was indeed the belt's retirement, the plan going forward is for the new WWE title belt The Rock introduced in 2013 to be the long-term title belt for the WWE World Heavyweight Championship. In fact, WWE has only listed that belt to represent the WWE World Heavyweight Champion on the Superstars page since the unification.
Here's a screen shot:
The new WWE title belt is used for the WWE World Heavyweight Championship history here on dot com as seen in the image below:
Another telling sign is WWE listing Randy Orton as the final World Heavyweight Champion after winning the unification bout at WWE TLC 2013 on December 15, 2013.
So to recap, while the World Heavyweight Championship belt could still be used, the long-term plan is for the WWE title belt The Rock introduced in early 2013 to be the belt for the WWE World Heavyweight Champion. That belt cost more than $50,000 to make and was in production for a year and a half. For those that missed our stats on the belt when it was first introduced, you can read about it at this link.