I don't thing Apple really has the cache anymore to hold two back-to-back press events like this. They would be skewered in the media, and rightfully so.
I agree that the event this week will likely the narrowly focused, and other stuff will come as a regular press release.
Regarding overlapping customers: "If you don't cannibalize yourself, someone else will." -SJ. I think Apple still operates by this mantra. So what if iPads cannibalize sales from Macbooks, or vice-versa? As long as the person isn't buying a non-Apple product, it's all good to them.