iTunes will only sync with iOS and iPod devices, however depending on the source and format of your music there maybe a workaround to allow you to sync to lesser devices such as Windows Phone.
Firstly if you are buying music from the iTunes Store, this has always been in AAC format, and for the last few years has been unprotected. It is possible to get Windows Media Player to accept AAC format tracks (assuming they are unprotected). In fact WMP12 in Windows 7 accepts AAC tracks as standard and even older versions of WMP can be made to accept AAC by adding a free codec and a plugin to allow reading MPEG4 meta tags (as used in AAC files).
If your music comes from CDs then as long as you import them as either MP3 or AAC then you can also share them with WMP and then on to Windows Phone.
It is possible to also share Apple Lossless (aka. ALAC) files between iTunes and WMP but these will not work on Windows Phone.
Once you have got WMP able to accept AAC files you can set it to monitor the iTunes library folder for changes and it will automatically add new files, this can be done with out having to make duplicates of the files.