It turns out that, to go with my shiny new iMac, I am going to need a shiny new scanner.
Canon have just confirmed the utter non-existence of Intel drivers for my D2400U. So now I have to hunt down a not too spendy scanner which will be good for scanning old photos and 35mm negatives. Preferably one with a holder that will actually hold the negatives flat unlike the one that came with the Canon… Oh, and of course I have to find a home for the old scanner as well.