The 430ex will be able to be triggered by the on camera flash as well as by an st-e2. The 7D and 60D don't use infrared to trigger, but they use the on camera flash to trigger flashes, like Nikon cameras. They don't quite use IR like you say, so you will be using the on camera flash to trigger other flashes, but on the 7D you can turn off the on camera flash so that it will only be used to trigger the other flash and not illuminate the picture.Not sure if that made any more sense.
Most of all this is Greek to me. I want the 7D. I have no plans to go into full frame cameras and it is the best I can afford. Then I know I want a great wireless flash system. That is kinda where my problem is. The ST-E2 and 580ex IIs sound like a really great combo but I don't know anything about it to be honest. The price is a lotta bit high as well.
Is there a cheaper method that would be more appealing to me? What would I look for in a flash to have a decent wireless system? My brother has a cheap flash that runs off of visual of the camera flash. This I do not like because I may not want to use my camera flash at all.
Looking at the basic info on your pieces, this does sound like something I would like, a bit lower class of flash for less money though. My only requirement is that is is Canon brand when at all possible. I mostly operate with mid grade gear and want to keep it there when possible.
So in more simple terms, the 430ex will work off camera, but unless you go the pocketwizard route or st-e2 route, you're going to be stuck using the on-camera flash to trigger your 430ex.