We have begun working on our magazines in the same fashion. 1024x768 at PDF format. Text and images look fantastic on iPad1&2 and the new iPad. Make sure you are using quality art to ensure quality images on both iOS screens. Keep in mind any overlays will not render as a PDF so plan ahead. If you have type in an overlay, OR an entire page that scrolls. it will not appear crisp. I reccomend testing as much as you can. If you cannot live with a few pieces of your issues being a little rough around the edges (literally) then conisder redesigning those few pieces.
As far as Android, I kind of have the same question. However, what we have noticed in trying to solve this problem is that there is a declining interest in the Android platform for our magazines. Over the past 5 months our number of active Android users has dropped 53 percent while iOS is constantly increasing. At this point Android devices make up a total of 5% of our total tablet readership. Before we resolve this Android question here, we may pull support for the device period until it makes more sense to invest the time in creating a second mag for it. If Android could accept PDF pages we would have no issues at all and would continue support but with this lack of interest it is hard to justify
Hope that helps,