The PS3 and 360 versions of Virtua Tennis are getting patched to fix the online:
http://www.seganerds.com/2009/06/09/virtua-tennis-2009-patch-goes-live-ps3360-versions/
Could the delay of the Wii version be due to patches not being possible on the Wii, so Sega is fixing it before shipping?
My Mario Kart Wii friend code: 2707-1866-0957