As far as I understand it, it'll only work if the new board uses the same RAID controller.
Even so, It's usually adviseable to do a reformat/re-install when switching motherboards. If you get another nforce2 board then you might get away with it though, as the chipset is the same.
I have no personal experience with using RAID 0 arrays, this is just information I've read in the past.
The safest option would be to simply replace the motherboard with another of the same make & model. That way it'll definitely work

. I didn't think there was anything particularly <i>wrong</i> with Gigabyte boards - personally I'd rather get a GigaByte board than an Asus one, but that's just my opinion.
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Epox 8RDA+ V1.1 w/ Custom NB HS
XP1700+ @200x10 (~2Ghz), 1.4 Vcore
2x256Mb Corsair PC3200LL/1x512Mb Corsair XMS PC4000 2.5-3-3-7
Sapphire 9800Pro @412/740