Actually, it's not meant for ripping. Slysoft is releasing this new program so you can watch HD-DVDs on your PC without having to upgrade to HDCP compliant hardware.
As of now, there's really no point in ripping it. HD-DVD media is too expensive right now and you're not going to want to fill up your HDD with a bunch of 15-30 GB movies.
Ripping HD movies will become important later on when HD-DVD becomes more prominent and they lower the prices significantly of both the drives and media. By then I'm sure slysoft will be ready.
Slysoft probably figures you can go out and buy the xbox 360 HD-DVD drive for $200 and enjoy HD movies on your PC using this new program. Makes sense. Just about every PC monitor is at least capable of 720p.