it appears likely that Blu-Ray players WILL be able to play older tech stuff (i.e. the older recensions of DVDs).
They do. It's just that Blu-ray players don't play HD DVD and vice versa.
It will be interesting to see what develops from this point on, and whether the Industry will be able to coax consumers down yet another yellow-brick road of upgrading any and all movies and shows they own to the new format. I'm not holding my breath.
Well, like I said, I doubt that a lot of product will ever be upgraded to the newest formats. Big titles with broad appeal probably will if upgrading improves them in any way. But so long as the new generation players continue to be backward compatible (meaning they'll play older DVD formats), it's probably not likely smaller titles will be upgraded/reissued.
Given how quickly video technology changes, what will be funny is that in 20 years people will probably be laughing hysterically that there ever was something as "antiquated" as DVD. Who knows what will ultimately replace it - but something surely will. Though in 20 years most of us will probably be too old to care.