If you are no longer able to connect to your NAS after updating to WD 2go 2.0, go to mobileOS/Settings/Applications/Manage Applications/WD 2go and select Clear Data. This will remove all attached NAS devices and will purge any data in the app cache. You can then use WD 2go auto-connect on LAN to re-add the NAS.
If this fails, uninstall the app and re-install, then auto-connect.