I see that in the 2.x days this package update slipped by me, as the -dev package was not also updated, or downgraded in this case. But being the 2.x repo, 2.x has not seen a package update in a long time.
I had made the ruby extension in the early days when we were trying to put together a base set of packages to make a workable distribution, though I am very familiar with ruby. I see on their site that ruby on rails needs version 1.9.2 or 1.8.7. From what you are saying, 1.8.7 would be the best version to have in the repo. There is nothing that calls directory on ruby.tcz in it's dep file in the repo, so I can revert it to 1.8.7 with likely no issue.
Since you have a vested interest in the ruby package and seem to have knowledge of ruby, would you like to maintain it in the current repo? That would give you a good say and control in when it is time to update it.