Let's see how that "open source" claim works out. Is the format itself open as e.g. Linux is, with "crowd" development? That's hardly possible, there needs to be a well-defined format with consistency and quality control, which delivers reliable performance in professional and home environments. Or is the format fixed, but its specifications available to the public, along with a public license to build encoders, decoders and other tools? That seems nice, but still the question of quality control and proof of format conformity is open, some central entity (probably DTS) has to ensure that, and this work has to be paid by someone, probably the tool developer. This gives DTS control over who is developing/selling what kind of product - not my idea of "open source". Another alternative are standards such as MPEG, which of course are subject to conformity tests and royalty payments, too. In the end, I don't believe that there can be a really "open" 3D-sound standard or format, since this is not the IT world where users or admins have complex installation and maintenance tasks and where MS or others send patches and updates on a weekly basis.
Another issue: Where is the DTS:X content actually coming from, if we consider the film industry? DTS has sold its cinema/professional division to datasat, and datasat collaborates with Barco, who is the partner and distributor of Auro3D. Is datasat going to promote both Auro3D and DTS:X to its studio customers? Hard to imagine, the studios want exactly 1 relevant format. Will Auro3D and DTS:X be (re-)specified to be compatible or even identical? The Auro guys have started to talk about object-audio but still their main claim is the 3D soundfield which requires fixed speaker locations and feeds, while DTS:X is all about objects and scalability. Is DTS reaching out to the professional market again, becoming a competitor to its own former professional division? Could be, datasat seems to focus on their Auro3D cinema processor and also on audio for 35mm film, so there is no technological link to consumer-DTS. That doesn't make it easier to conquer the studio market, and explain to those customers that there used to be professional DTS, which has become datasat, and now there's a new and different DTS which competes with datasat...
Next question: cinema installations. Atmos has obviously quite a headstart there, probably for a large part based on massive sponsoring by Dolby. I don't think DTS has the means to repeat this sponsoring effort. I am however curious whether the Atmos cinema installations (amps, speakers) can be connected to a DTS:X decoder so that both formats can be played (if Dolby didn't prohibit that contractually). But even if that works, moviegoers and cinema owners, as well as home consumers, have to be convinced that they need yet another 3D-sound format. Too much choice can bring confusion and dilution of the whole 3D-sound proposition, that's why I am hesitant to whole-heartedly welcome DTS:X. One well-known, appreciated and prevalent sound format (whichever it may be), even if proprietary and imperfect, is better than having a bunch of irrelevant formats of which none is strong enough to achieve the necessary wide acceptance of 3D-sound.