This may come as a bit of a surprise, but Kineto, purveyor of VoLGA software, has announced a dual-function client for LTE phones which supports IMS voice and VoLGA. Wow.
First question: Why?
It seems that Kineto is trying to make the point that VoLGA is the natural first step on the way to IMS.
Also, the announcement points out that handset vendors will need to support both voice solutions to ensure compatibility with roaming. Ie not every network will support IMS, so support for VoLGA as the interim solution, is a must.
It seems that the client is field upgradeable, which de-risks an LTE handset, and gives IMS time to grow and develop.
All in all, this is a positive step forward for LTE.