The read/write support appears to be in the kernel, but even though it shows as mounted r/w under mount I still get read-only filesystem errors. Has been reported in channel that other people also get these errors, unknown reasons though.
Not a bug - read the help text for the write option - you can only write to files when you do not change their size. Yes, this makes it pretty useless. Linux will probably have full NTFS write capabilities in a few months time.