It's included on the new HTC Touch, so I would not be surprised to see it pulled out and available somewhere as a stand-alone add on for HTC devices...either through official channels, or not so official

Keep an eye on the XDA-Developers site for such things. Their link is located in the side bar of this page under "Mobilegadgetnews Friends".
I have used the CVC on the Touch, and it works pretty well once you learn how to use it...which doesn't take long. When you initiate the program the screen has the scripts right there for you to read (just insert the name of who you are calling etc). I like that 'cuz I'd always forget exactly the words I am supposed to use to talk to it. That's due to the fact I just don't use it enough. If I used it all the time, it'd become second nature no doubt.
It's not perfect though, there is at least one contact I have not been able to EVER say right to make it dial. It's an easy name so I don't understand what the problem is. Getting it to just open a contact is pretty much hit or miss...mostly miss. I get frustrated with any of these types of programs (I've tried MS's too) that I just long for the good ol'days of voice tags. Which the Touch can still do. But, then again I don't have a very big need for this sort of dialing so my motivation to use it isn't high.

Good luck!
Devices: T-Mobile MDA (Cingular SIM), i-mate SP5m (sitting in a drawer at the moment while I attempt to migrate to PPC permanently), Cingular 3125 (unlocked and in use on T-Mobile), Motorola MPx220 (retired), Motorola MPx200 (retired)
Accessories: Plantronics Explorer 330 & 2G Patriot Micro-SD (use w/MDA), Kingston 2G mini-SD used in SP5m, Plantronics Discovery 640 & 2G San Disk micro-SD (use w/3125), Jabra A210 BT adapter + Motorola HS805 (retired)