I've spent quite a bit of time over the last week or so getting the Opie plugin for OpenSync ported to the latest 0.3x branch (ie, trunk in svn). 99% of the job is done, all that is needed now is testing and a few fixes here and there. If you're brave, and make backups, you can check out OpenSync from svn and give it a try :)
In the process of porting I've also fixed a few things:
* scp support now actually uses scp/ssh instead of sftp, so that you don't have to install additional packages to have a secure connection (it works with dropbear that is included in most handheld distros by default). You will need to set up key-based authentication however - there's no mechanism to enter an ssh password at sync time.
* scp can now sync notes
* Improved error handling in a lot of places
* Lots of refactoring and code tidying
The 0.3x branch will eventually become the next stable version of OpenSync, 0.40, but there's still quite a bit of work to be done before then (see the TODO list). There are a few things I'd like to add to the Opie plugin, mostly along the lines of making it more robust, but also some minor features eg. supporting the Opie-Notes application. In the near future I'd like to also look at adding support for the SQLite backend in Opie, however at the moment the SQLite backend has no mechanism for retrieving data remotely for syncing purposes, so that will need to be added in Opie as well.
I've probably mentioned it before, but I have to say I'm pretty excited about OpenSync - it's a powerful syncing platform and one that has a huge amount of potential. We need to not only keep pushing the development forward, but we also make it more visible and accessible to people. KitchenSync with OpenSync as a backend is now in KDE 3.5.7, gnome-sync has just been released, and I think once KDE 4.x comes out with Akonadi and OpenSync support makes it into Conduit (which I understand is on the cards) we will have a bit more exposure.