I say those "big options" don't go far enough.
I agree that using a Dvorak (or another alt layout) won't offer much improvement for casual users, even apparently moderate to heavy users. I do think Dvorak offers a lot to extremely heavy users, as using it simply makes my hands more comfortable even if speeds are comparable (when I've been using each layout). But for most folks, the limitation is in how much effort they put into typing, not how responsive their keyboards are to that effort.
But, I don't think that modifying a key map goes nearly far enough to tapping the potential of the keyboard as an input device. Our keyboards no longer need to literally shift paper carriages and/or baskets of brass levers. One thing I really like about the TextBlade is how it combines multitouch with mechanical actuation to move each finger's "keys" closer together without sacrificing tactile feedback. Other innovative keyboard designs place many actions under each thumb, and/or increase the different behaviors of each key (as with chording, tapping, and sticky keys).
Realistically, I think on-screen keyboards are the way of the future for the mass market. Once you already have the touchscreen in place, even cheap keyboards are stunningly complex, failure prone, and expensive. But the rest of us will be served by companies like Waytools, allowing us to get a keyboard that is far better that today's commodity offering, and far more tailored to our individual wants and needs. I like that vision of the future.
...as a postscript, I'll add that the most interesting thing I've found in designing my own keyboard is that Qwerty is actually rather well optimized -- if numbers represent a significant portion of the input, and if the T and Y keys are home keys for the left and right index fingers.
...oh, and a PPS: it has been far easier for me to retain my normal Qwerty speed while learning how to type on a Dvorak-based keyboard with a different physical layout, than it was when learning Dvorak on a standard keyboard. So, when making the jump to a new style of keyboard, such as when you get a TextBlade, would be a good time to learn a new layout if that's the direction you want to take.