With iSync 2.2, included with the Mac OS X 10.4.6 update, Apple have finally cracked a problem which has bugged me for ages: reliable sync with Nokia phones. Previously, most Nokia sync has been using a special iSync Agent Series 60 app (which only worked with some series 60 phones, and which usually lagged behind new phone models). This resulted in funny hacks like my own N70 sync plugin.
Apple seem (judging from the behaviour I've seen on my phone) to have finally implemented SyncML support in iSync: A sync in iSync now causes my N70's built in sync app to fire up.
This means several important things. First, it should hopefully mean that new Nokia phones are supported as they appear. Second it means that you can get rid of that annoying iSync Agent app on your phone.
Third, and most important for european Mac users, it means that Series 40 phones, like the ubiquitous 6230, are supported. (Check out that vastly extended iSync supported devices list.)
So, if you're using my plugin then, before you update Mac OS, remove the device from iSync, delete the N70 plugin you put in ~/Library/PhonePlugins, and then enjoy the new sync experience after you update! (Oh, and their N70 icon is much better than mine...)