I think it's already on their minds. With Office 2007, they spent so much
time implementing the extensive new UI, that they ran out of resources to
make all of the changes they intended.
Could you work around this by using multiple series which are formatted
identically? You can have a total of 256k points in a chart. That's enough
to cover each pixel on a chart with multiple markers, assuming 1-pixel wide
markers. It's probably also enough to choke Excel 2007's chart redrawing
functionality, from what people have reported on these forums.