It seems as if the Joomla! Developer Portal forge.joomla.org is currently down. This is a problem because most of the VirtueMart downloads are hosted there.
An alternative are the official project pages on sourceforge.net: http://sourceforge.net/project/platformdownload.php?group_id=147802. There you can find the packages and the eCommerce Edition for download.
Let's hope the Joomla! Forge is back online soon!
