Should the installer pin packages on debian and ubuntu?

I've recently been trying to puppetize some of the things in the virtualmin install script (hoping to release it... eventually). The installer script is pretty robust, as well as well written and documented. (I look forward to seeing some of the commented out sections complete)

So, going through the installer, I reached the portion where it says "make sure we're running our version of packages if we have our own version." and was wondering a few things:

• On Debian/Ubuntu, Is this still a problem or does the Virtualmin Repository versions superseed the distribution ones?
• If it is still a potential problem, would apt pinning would solve it on Debian/Ubuntu?

Thanks for all the great work. Virtualmin really is a solid and robust product.