Currently, you need to use ADFS to sync passwords, or,if you dont want to do ADFS, you can do DIrSync and use the MessageOps tool to sync passwords. Thats a good deployment of an "ADFS Lite" kinda thing
Now, the exciting news is, Password sync is coming with DirSync.
So, all you need to do is research whats involved with "DirSync" and thats it.
I believe next month (June) is when the DIrSync is going to be updated to include Password sync.