According to one of our sources, Asus doesn't have an X48 design, so those hoping that the new Maximus Formula and Extreme boards were going to feature this chipset, you'll be disappointed. The other two X38 boards are the P5E3 Deluxe and the P5E3 WS Pro, the latter of the two being a workstation board.
Asus is expecting to have its X38 boards out in retail within the next couple of week's time, although it might even be sooner. If this is indeed true, then Asus could be the first company to have X38 based boards in retail, but time will tell.
We'll try to dig deeper into the X48 story and maybe things will become clearer during IDF, as Intel might officially explain the X48 situation then. If the information we wrote about earlier is correct, then the X48 might just simply be a faster version of the X38 which will be released later this year.