Joe. Jaquith just answered that...
"Often you 'can' move the OS drive to a new PC if there's no RAID or with a RAID a compatible chipset i.e. Intel to Intel"..... Means no new install. Simply replace the mobo and plug it in as is.
"Further, once moved you'll need to install the Chipset (INF) and remainder of the drivers for the new MOBO." Now hes just explaining that once you have it installed turned on etc. To go to the mobos website and get the chipset and drivers for it so it works properly