The coolness factor of the experience itself is definitely there, but it won't ever catch on unless the displays are extremely lightweight, unintrusive (regular pair of glasses unintrusive), and hi-res. But companies don't want to invest in advancing the technology, because the demand isn't there. Thus the catch-22 that's kept HMDs relegated to a niche market of enthusiasts with lots of disposable income.
Releasing a consumer-friendly HMD right now would be as likely as releasing the iPhone in 1998, or the DS. IMO if it were to ever catch on, it would be in the future when the needed technologies have become advanced enough and cheap enough on their own, and some company has the idea to "go retro" and combine them into a consumer-friendly HMD.