gamerprinter
Mapper/Publisher
Well, with the OGL and OSRIC, 3pp can already do this (though I'm not sure what is going to happen to 4ed), but I guess what I was arguing was that the point of releasing new material would be for WotC to generate constant income from older editions.
If I were to play the older editions, which I don't (I'm only referring to pre-3x), the only thing that would be worthwhile to me is adventures. And though some may dispute it, I think WotC has never been good at creating adventures. So WotC could certainly try to generate income from the older editions, it seems that WotC can't create a worthwhile adventure for any edition (even the current one). So at least to me, WotC has no means of generating revenue from older editions beyond selling PDFs of already created content.
I don't and won't use DDI, so whether its the best route for WotC revenues, I don't know, but it won't be a revenue stream from me.