This is one of the typical nonsensical answers you get from support people. I do sync my N800 via SyncML with scheduleworld.com, so yes, it does support SyncML. (Via a third party add-on, but this only proves that SyncML is only a matter of software, not a matter of the device supporting it.)

The underlying problem with ovi is that they restrict it to certain models at all. This is not how SyncML works. SyncML is an established standard, and clients only need to know a few settings about the server in order to make a connection and exchange data.
For whatever reason, Nokia doesn't tell you these settings for Ovi but insists on sendig you a text message that will configure your - phone. Phone because "sending a text message" of course by definition rules out all other devices such as Internet Tablets or desktop PCs.

This means you cannot (by design) use Ovi to

• sync your PC with your laptop
• sync your phone with your N800
• sync your N800 with your PC
• sync two phones if one of them is not in the list of supported devices (even though it perfectly supports SyncML)
• ...

and will never be able to do so, no matter how much they improve it.

I don't see much use in this service, then.

(BTW, I tried Share on Ovi during the last days. They fail to interpret geotags in the EXIF-information of images correctly. The bug is known since early 2008, but is not being dealt with. Support forums are closed until further notice. What is this? A tiny startup with 3 people working on it in their spare time?)