The IP's should always stay the same, as VMware's DHCP server will continue to hand out the same DHCP addresses to the same VM's, as long as you don't do something like deleting and readding your network interfaces of your VM's. But, that aside, the Landshark process was built to handle the unlikely event of a network change and update everything to keep it all working. If you should find yourself in such a situation, just watch the Landshark video on network changes, where I cover Landshark resolving the changes.