Warning: this blog post is a complete waste of your time!
On the Relevance site, I saw a link to this fascinating analysis of the connections between the first Star Wars trilogy (episodes IV-VI) and the second one (episodes I-III). As much as I'm loathe to admit it, I've done some thinking along these same lines, especially since 2 things have recently happened: 1) I got a new HDTV and 2) HBO has turned into the "All Star Wars Station" (but only for episodes I and III -- they must not have rights to II). You should probably read the analysis before you go on (or it won't make much sense). I'll wait.
In fact, the only flaw I can find in the analysis is the fact that the Jawas weren't at first going to sell R2D2 to the Skywalkers -- it was only after the other similar droid blew up (maybe R2D2 did something to him in the hold of the Jawas' ship?) But it kills the idea that the reason they ended up at the Skywalkers was some sort of deal with the Jawas (unless they double crossed him). See, I told you this was a waste of time, right?
Actually, I distinctly remember interviews with Lucas back in the late 70's where he talked about a trilogy of trilogies (it was supposed to go episodes IV-VI, I-III, and then VII - IX). He has since retracted that statement (and claims he never made it). Whatever. Given how much work it is, I completely understand.
But I always thought that it would be cool in episode IX for C3P0 and R2D2 to suddenly reveal that they are in fact the keepers of the force, much like some of Asimov's robot stories where the robots turn out to be the guardians of mankind while pretending to serve him. And, if you take C3P0 out of the equation (in light of the analysis above), then R2D2 can be said to be the guardian of the good part of the force. That would be cool!
When I want to waste some more of your time, remind me to tell you about the plot idea I have for the origin of the Borg...