Fixing MacTubes will not be trivial. Although I have the source code for it, which the author graciously provides, it relies on the older GData framework. Unfortunately, the API is so different that it will need to be completely rewritten and some features will probably not translate. If/until that happens, the MacTubes Enabler (MTE) will no longer be supported, though the QuickTime Enabler (QTE) will still work for those YouTube videos it generally supports (it relies on a different method which Google will probably break again next week), and of course WebM still functions on YouTube if your Power Mac is fast enough and the video is available in that format.
I suppose this is a good time to mention that I've been working on a sandbox solution for "things like this" as a secret project for some time on the side. I will only say that it exists as an internal proof of concept and actually works, but I'm not offering more information until I have something releaseworthy and that's not going to happen until 38 comes out. For the time being, we appreciated all the work that went into MacTubes and its related applications, and we will be overjoyed if they are fixed, but I'd rather just find a way around Google instead of playing their stupid little games with their moving-target APIs. That is where our effort will be focused post-38.
31.7.0 is scheduled for testing availability this weekend, just in time to upgrade your mother's computer, because she loves you and misses you and wants to know why you never call.