the current stable version of the Apache(2.2) doesn't have that feature, but the 2.4 does have the IF directive:
so you have to create two virtualhost for now.
but you can set some stuff through environments or apache global variables and use that in you virtualhost config (setting the documentroot for example), this way if you want to change that, you can do it with just one line of modification.
and of course, you can use Include to do something like this:
ps: SNI will be mainstream years before the IPv6 adaptation...
currently the only major browser that doesn't support it is the Safari and IE on Windows XP.