The current stable version of the Apache(2.2) doesn't have that feature, but the 2.4 does have the IF directive.
You have to create two VirtualHosts for now, but you can set some stuff through environment or apache global variables and use that in your 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.
Of course, you can use include to do something like this:
ps: SNI will be mainstream years before the IPv6 adaptation. All of the mainstream browser support it already assuming you are on a supported OS.
edit: as fooquency spotted you can't put SSLEngine On to an If block so my answer is wrong.