Yep, from what I've tested so far on the PTR, you can just replace the "Live" Ace2 libraries in the /Libs folder with their TBC equivalents and Visor2 will work just fine in the next patch or on Beta.
I actually did something similar in the past with the script commands in a little .lua file. One thing I noticed though, particularly with the action bars, was that WoW would periodically reset them on its own accord back to their original positions. This is something that Visor/Visor2 overrides with the "Naughtiness Eradicator" functions at the bottom of each of the module files. That's the main reason I went back to Visor, and hence my desire to convert it for WoW 2.0 use.
I've been considering using the old interface again, the standard due to sometimes feeling that addons aren't as responsive as the standard is(yes yes it might just be something I imagine but hey, if I manage to fool myself into thinking it and also gaining some memory, why not) and I just would like to thank you for taking the time and effort to rewrite Visor to ace2. So in short: Thank you ! :)
I have this in the SVN now too. However, the version of AceLibrary that got pulled in when I committed it is causing an error (unexpected symbold near "..." on line 27) or somesuch. If anyone does grab this copy before Tuesday, you can just overwrite AceLibrary.lua with a copy from another addon and it should work.
Not sure where else to mention this error, so hopefully one of the lib authors reads this thread. *grin*