X3D (Extensible 3D Grpahics)is going to be the successor of VRML97. The Web3D-Consortium and the W3C are working on the Standard, which is likely to become an ISO Standard as VRML2002

It is based on XML and will be backward-compatible to VRML97. It is going to have a relativly small core and a lot of components extending it. That makes it fast.

Theres also going to be an open source X3D Browser written in Java called Xj3D