Very good, in my opinion.
3D TV are useless without 3D content, and this content is immediately useful inside head-mounted displays. Just like surround sound at home did not inhibit portable music players - the Walkman or the iPod - 3D TVs don't inhibit HMD sales.
With 3D TVs, an increasing number of users are exposed to the power of 3D and are thus stimulated to come up with new uses.
3D TVs will drive 3D games, but HMDs offer 3D gaming in a dynamic, 360 degree surround video environment that a TV cannot offer. HMDs can be portable and battery operated, whereas TVs are stationary and power-hungry. You can run around with an HMD on your head (especially with a wireless video link) but no one would consider running inside a room carrying a TV.
Do advances in fuel economy of cars impact air travel? Not really. Similarly, the use cases for TV and HMDs are different in other aspects as well. TVs are better suited to group viewing, whereas HMDs offer privacy. TVs provide all users with the same viewpoint, whereas embedded trackers inside HMDs (such as the zSight) can offer dynamic and individual viewpoints. Some exciting 3D content comes from animated features. How long before such content can be streamed and changed depending on head position? This would be excellent news for HMDs that can provide great immersion.
You can get some great 3D TVs for $2500. When will you be able to get great HMDs for $2500? Perhaps as soon as there is demand for 6 million HMDs a year.