I've created some Slackware template caches that are newer than the 2-year-old Slackware 12.0. To be honest, though, I've never used OpenVZ before today, so I apologize if I did some things wrong. http://technoized.com/storage/openvz-slackware/
I found your templates very useful. Maybe you should consider emailing contrib@openvz.org so that they are listed on the openvz.org site? I was inspired by these to create one myself - an i386 Slackware 13.0
I actually didn't know where to go to get them listed, but that sounds like a good idea.
Saves bandwidth if nothing else I think they get copied to mirror sites automatically, once they've been wget(ed onto downloads.openvz.org