Yes, the screen acts as the driver info centre as well so you can have a choice of temperature, trip info, sat nav or media files being played on the screen.
Never tried playing a DVD but the built in centre plays AVI's from the SD card slot, this is only while the vehicle is stationery though (unless anyone knows how to disable this...?!!)
If I remember over the weekend, I'll try a DVD.
There is a replacement screen you can put in there which I've seen advertised on various eBay type sites, gives you DVD, TV,iPod connectivityetc. Just over £2k I think and not really of that much interest to me though.