Using a PIXMA IP6600D connected through an Apple Extreme Base Station here. Works like a champ! Low ink and other warnings come through just fine. The separate ink tanks are a big plus, too. And quality is great.
Well, I bought the MP530 and Amazon delivered it in two days. I'm pleased with the printer but only the print and copy functions are working under Leopard. Scan and fax software is still under development so I'll be patient.
I also got a feel for Canon customer service as the plastic locking tabs on the cyan and yellow ink cartridges were broken off when I opened the box which prompted a trip to Walmart so I could use the printer. I emailed Canon about the issue and they are sending me two new ink cartridges.
I just got it 2 days ago, downloaded the latest software from Canon's website. Everyhting is perfect with Leopard. Previosuly I have purchased the Lexmark XG9350 which I returned it; there is no Leopard driver for it. The MP530 lacks networking, but otherwise is a solid choice, and it looks good too.