My Network configuration is as follows:
192.168.2.1-192.168.2.255 (Subnetmask - 255.255.255.0 )
192.168.3.1-192.168.3.255 (Subnetmask - 255.255.255.0 )
I have only one Domain controller with two NIC cards.
One NIC card is connected to 192.168.2.0 Network(via one switch) and
other NIC card is connected to 192.168.3.0 network (via another switch).
Will this one server serve as DC for two networks ? (One Domain is enough).

Please see the Network configuration at
http://img528.imageshack.us/img528/8596/networkf.jpg