There seems to be 2 main types of people who are seriously interested in the Oculus Rift. Those who just want to peek their head in a virtual world, and those who want to be able to physically run and jump and flail their body around in a virtual world. I'm definitely one of the former. I think those wanting the latter will be bitterly disappointed.
I'm fine with the limitations imposed by using a gamepad or mouse/keyboard. Running around has very little appeal to me. Sure, it might be a nice way to exercise, but I think with the current state or even the near future of technology this would only come off as a cheap gimmick. To have satisfying complete immersion in a virtual world I think you would need some sort of direct neural stimulation and muscle override.
Beyond the massive gaming improvements that comes with extremely high quality 3D depth and the additional natural input of being able to look around, the oculus delivers something that hasn't been delivered before: presence. Not to be confused with something like the holodeck, "presence" is a much more modest (yet still profound) sensation of being somewhere, though not necessarily physically. Inhabiting a region of virtual space, even as a floating ball of non-interacting consciousness is a very appealing concept to me.
What I would really like to see in the iteration after the first consumer release is smell. This would be an incredibly difficult problem to reliably solve, but I think it would go a long way to the type of experience I ultimately want out of VR. Along with this I would like to see great eye tracking/face tracking and hand tracking (for virtual interactions with other people). All of these things the Oculus guys have expressed interest in pursuing, so it seems some of my wishes might come true in the future, assuming most people don't expect the Holodeck from Oculus Rift Consumer Version 1.