Recently we added the UDF driver by Alter into ReactOS trunk. It builds nicely now due to the efforts of Amine Khaldi and now even for AMD64 and ARM, but booting with it is impossible. Attached a log file made with r68146 on a MSVC2013 build. For a easy way to reproduce, install http://dwn.alter.org.ua/downloads/dwn_1_5_12_sp2.zip on ROS, shutdown, replace dwudf.sys with our built udfs.sys and bootup again. It's not added to the ISOs as long as it does nothing useful.
UPDATE: sys file already is there. You just need the reg files added here, but beware! These are for dwudf.sys, so you have to fix the name to our udfs.sys