As you know, per the VRT license, registered users must wait 30 days between the time of release of the rules and when they have access to them. Subsequently people who are not subscribers could not run the Snort version 188.8.131.52 release of the older Shared Object rules available from the VRT.
Well, since the release of 2.9.1, it's been 30 days now, and those that couldn't upgrade to 2.9.1 because of this restriction, your days of waiting are over.
Registered users have now passed the 30 day mark, and can now upgrade to Snort 2.9.1.
Please be sure and read all the blog posts that are associated with Snort 2.9.1 here.