It will be a gradual thing, not an all-at-once thing. Pretty much 1.2 official would be considered the last snapshot of the "old" AVWW, and I'll be sure to hang onto the installer for that somewhere. Hopefully others can mirror that elsewhere, as I don't really want to pay for the bandwidth for an old nostalgia version, though.
It may yet still be a few weeks before any of the new stuff actually gets integrated into the game, because there are many layers of work before the first batches of stuff are finalized enough to be implemented in that way. But then once the first batch hits, it will be pretty continuous after that.
Someone could always just archive the old graphics, and keep a "texture pack" for them.
Sure, some interesting things may need to be done to the original files when scales change, but it might be of interest to some people.