I have no intention of upgrading at least 95% of my collection, and recommend that anyone who feels the same way should spend the money potentially saved on a really top-class upscaling player like the Oppo 983. That's what I did, and the results are phenomenal - so good, in fact, that I have to double-check DVDs I'm reviewing professionally on a bog-standard player to make sure that I don't miss defects that the Oppo's software has ironed out (interlacing, for instance, is simply not an issue any more).
That said, the differences between SD-DVD and Blu-Ray are still blindingly obvious - Disney's
Sleeping Beauty conveniently comes with both versions, sourced from the same transfer, and it's not exactly hard to tell which is being played at any given moment. (My kids only have access to the DVD; they only get to watch the Blu-ray when I'm around to supervise!)
I think the reality is that there will peaceful coexistence for a long time to come, and a lot of the stuff like the superb Eclipse set of ROSSELLINI HISTORY FILMS will never make it to BR, and should be fully enjoyed and appreciated in its lovely (and not aesthetically inferior) SDVD incarnation...
There is absolutely no aesthetic reason for at least 90% of television history to be reissued on Blu-ray, unless it's to take advantage of the greater capacity so entire series can be crammed onto a single disc. Even if a programme was shot on film, the chances are that the final master was on an SD video format - while you could probably get a stunning Blu-ray out of, say, Ken Russell's
Elgar (shot on 35mm, and I believe the original neg survives), that's very much in a minority.
In fact, while the BFI's upcoming Jeff Keen Blu-ray box features three discs, just one is a Blu-ray, because Keen often worked with 8mm film and SD video formats which really don't benefit from an HD transfer. So transferring the lot to HD/Blu-ray would significantly increase the production budget while achieving a pretty negligible quality difference - and as a side-effect of this you'd almost certainly end up with fewer films. So I think they've got the balance pretty much right - not least because the DVDs can be duplicated across the DVD set as well as the Blu-ray box, thus achieving greater economies of scale for what is clearly a commercially risky project.