I can understand the need and want for a simpler rules set. I used to love complex rules sets. I thrived on the rules and loved new classes, new items, new combat modifiers and all that lot. Loved them. (I could also say that I've noticed a broad trend for many younger gamers to want more stability and control over their lives, and rules for a pasttime provide an illusion of that.)
Then as I got older, I came to the realization that was all crap. I embraced 3E and still do, as a nice and complete RPG set of rules that all work mostly the same and seldom at cross purposes. But I find myself over the last eight years wanting more for less. I think the toolbox approach is still the way to go but I want a smaller toolbox, now.
I probably wouldn't go as far as OD&D. The simplicity there is also an illusion created by simple incompleteness. It's something I've wanted to try for a while now, but I strongly suspect it would satisfy me about as well as Tunnels and Trolls did. After a time, it seems you'd go back to the same things that happened when I played OD&D: the GM will spend a lot of time filling in the rules, to the point that you might as well have bought 4E and saved yourself a lot of trouble. That could be a good thing for you, but for me I never could keep the changes straight in my head. In short, yeah, prep time might be shorter but you'll spend a lot more game time arguing about things or trying to do things the rules don't directly cover.
The way Diaglo handles it is probably the only way, but it seems like a hell of a lot of work on the GM and player's part to me, just from reading his posts over the years. I might be mistaken.
But I agree that I want a simpler rules set. So far, it seems like Savage Worlds will be the way to go but I want to try other RPGs, such as Hollow Earth Expeditions or FATE.