FUD Zilla claims the launch of the Intel X48 chipset has been delayed because Asus asked Intel to do so:
Asus decided to go full on when it comes to products based on the X38 chipset and has some nine SKU's based solely on the X38 chipset, but apparently sales haven't been as good as the company expected. Due to this they asked Intel to delay the X48 chipset until they could ship more X38 boards and clear out stock.
We're not sure why Intel listened, but it seems like the two companies are very close indeed. But don't despair, if you're waiting for the X48 chipset, it looks like it will finally launch towards the end of this month if all goes to plan, as Intel needs it to get the most out of their upcoming 1,600MHz FSB processors.
The good news is that there should be plenty of X48 available on the launch date as all Taiwanese motherboard makers are just waiting on the green light from Intel to start shipping the boards.