Do u think there is a high chance that the motherboard or cpu could get damaged by the psu blowing? There was only 1 spark, no smoke, the psu has short curcuiting proctection and stuff according to the manual.
There is also a small chance that something was accidentally shorted inside the case. After you get your new PS, do a "bench test" before installing everything in the case. Put the MB w/CPU and CPU hsf on a table or other non-conductive surface, install the RAM (but not drives) and video card, connect the PS power cables, and see if it boots up OK and you can get into the BIOS.
You might consider getting a cheap LGA775 Celeron or something to use to test out your MB once you get the new PS, instead of using your 6800. That would also help to distinguish between a MB problem and a CPU problem if you do have problems even with the new PS.