During the course of the last two years, several hardware devices were developed that implement the SyncML specification. A complete list of officially compliant implementations is available at http://www.syncml.org/interop/interop-compliant.html. Most of the devices are mobile phones. Some companies chose to test each device, others just tested their protocol stack for conformance. Since I do not have acces to a hardware devices that supports SyncML I cannot go into more detail.
Currently, only the top of the line phones support SyncML. But this situation will hopefully get better, when the SyncML protocol stack will become a standard part of any mobile phone.