There has been some discussion about this before, but I cant find it right now.
Basically DTS 96/24 is a new DTS format with higher sampling frequency (96kHz compared to 48kHz with normal DTS and DD) and 24 bit word length (same as normal DTS and DD).
To try DTS 96/24 You'll need a DVD encoded in DTS 96/24 format, an ordinary DVD-player with digital out and a receiver with DTS 96/24 decoder. You cant get DTS 96/24 from DVDs with only ordinary DTS (48/24). Also if you play DTS 96/24 material with a non-DTS 96/24 decoding receiver, you will get only DTS 48kHz, but it will still work.
In the future there might be more DTS 96/24 encoded movies, but for know I have seen only a few music DVD-V discs with DTS 96/24.
DTS 96/24 will give better audio quality than ordinary DTS, but I dont think it can compete with DVD-Audio.