Most of it already IS digitized.
Okay, what if they modified the license on the previous editions to match the OGL,

















JOYGASM!
Well this wouldn't help DDi. I was trying to construct a method that would bring DDi customers in using the older editions based on the other thread.
If they opened up, and I think there is other reasons hidden in why PDFs of older editions were pulled and they might not be allowed to use them in full, to OGL format, that is a different type of support, that wouldn't necessarily help DDi or WotC. Might be a good faith move, but not likely to have customers for the DDi or people spend any money with WotC, unless WotC has some kind of product to buy for those older editions.
And also, "the DDI" is not just the Rules Compendium. You want Rules Compendium support, and nothing else? No other tools?
If the VTT does integrate rules into it to bring up displays ons creen of monsters or such, and this can also be used to pull data form the older edition compendiums... in a <blank>ing heartbeat!
I have tools for every edition before 4th, so don't need them. There are still tools out there for older editions form long ago. Not the best things since they probably need to be run in DOSBox now, but still they exist, and not much in the way tools were really needed.
I don't fathom them ever making tools as decent a there was for AD&D, and those were even lacking in functionality.
But having access to the spell compendiums and magic item compendiums and a monster repository, plus the "rules elements" to be able to play the game with IS support for older editions, and what I am basically suggesting. Something that lets people have access to the older material, and when the time comes the VTT to be able to display that info just as it is said it should for 4th edition.
It may be minimal if the data is not added too, but it is support, and likely support that would get people to try and dump at least $10 into where they weren't spending a thing on DDi before if they didn't use the 4th edition material, right?
So one subscription fee gets you access to all editions, dungeon, dragon, vtt, and the other 4th edition tools.
There is even a chance for WotC than an older edition player might see and like 4th edition enough to try some of its products, should any books ever be printed for 4th edition again.
So support has many levels, but the most basic is having enough there to play the game with in order to get people drawn to the DDi and try or maybe use it.
Looking at the data over time to see how many people are using older editions within the DDi, would let the judge what other content to include if they want to add things. Who knows, maybe one day even add settings to it.