It has been a long time since we used the Sony Ericsson Sync service. However, the contact/calendar syncing tool is still around albeit for not too much longer. Sony Ericsson has confirmed that Sony Ericsson Sync will close on 29 December 2012.
Sony Ericsson says that SE Sync was “meant for old generation phones” and to create a more integrated experience for the end user it suggests moving to “Google Sync service for a more integrated experience in line with the favourite range of Google Mobile Services like Google Voice Search, Google Maps and YouTube.” It has provided full instructions here on how to go about this. Of course, you can use whatever sync service you like and SE also recommends Plaxo and UNYK.