Yes, We have a server up and running and have many people logging on each night. All you have to do is change your host file and connect through the in game multiplayer tab.
Go into C:/Windows/System32/Drivers/etc and open the file name host. Copy and paste the text below. Enjoy Civ iv Multiplayer
#universal entries
148.251.130.188 motd.gamespy.com
148.251.130.188 gmtest.master.gamespy.com
148.251.130.188 peerchat.gamespy.com
148.251.130.188 gamespy.com
148.251.130.188 gpcm.gamespy.com
148.251.130.188 gpsp.gamespy.com
148.251.130.188 gamestats.gamespy.com
148.251.130.188 master.gamespy.com
#vanilla specific entries
148.251.130.188 civ4.available.gamespy.com
148.251.130.188 civ4.ms18.gamespy.com
148.251.130.188 civ4.master.gamespy.com
148.251.130.188 civ4.natneg1.gamespy.com
148.251.130.188 civ4.natneg2.gamespy.com
148.251.130.188 civ4.natneg3.gamespy.com
148.251.130.188 natneg1.gamespy.com
148.251.130.188 natneg2.gamespy.com
148.251.130.188 natneg3.gamespy.com
#bts specific entries
148.251.130.188 civ4bts.available.gamespy.com
148.251.130.188 civ4bts.ms7.gamespy.com
148.251.130.188 civ4bts.master.gamespy.com
148.251.130.188 civ4bts.natneg1.gamespy.com
148.251.130.188 civ4bts.natneg2.gamespy.com
148.251.130.188 civ4bts.natneg3.gamespy.com
#additional stuff for japan dudes
148.251.130.188 civ4btsjp.available.gamespy.com
148.251.130.188 civ4btsjp.ms5.gamespy.com
148.251.130.188 civ4btsjp.master.gamespy.com
148.251.130.188 civ4btsjp.natneg1.gamespy.com
148.251.130.188 civ4btsjp.natneg2.gamespy.com
148.251.130.188 civ4btsjp.natneg3.gamespy.com