So who's going to be first to attempt higher resolutions on an iMac with external monitor? That video chipset will definitely do it, so it's just a matter of tricking the iMac into thinking it has a larger monitor attached. I know that monitor resolution support used to be signalled to the Mac by sensing for combinations of pin voltages on the VGA cable. Does anybody know how it's done on these new digital interfaces? Or is it completely in software (more like PCs)? If it's a software-only hack, that should be a lot easier to figure out and, er, "fix".