got their hands on Asus's upcoming X48 Republic of Gamer board, the Formula Rampage, and has done a quick preview of the board, although there are no benchmarks.
In all honesty, not much has changed from the Maximus boards, although this is a DDR2 version, which seems to contradict some information about the X48 chipset not supporting DDR2 memory, which has been mentioned in some materials that have made their way online.
The board doesn't feature the watercooling option, nor does it have eSATA, so we'd expect to see these features being added to the DDR3 version of this board, which we would guess will drop the Formula part in the model name.
You can find the preview here
with plenty of pictures and BIOS screen shots.