My understanding is that Watson is the name of the computer, and DeepQA is the name of the software or technology. They are both correlated.
Are there any computers/technologies other than Watson which are using DeepQA? Or is Watson the only computer which implements that software/technology?
I cannot say for certain, but I know of no such other uses (I work at the building where Watson is developing but do not directly work with it).
The DeepQA team's page (https://www.research.ibm.com/deepqa/deepqa.shtml) only ever references Watson as the implementation, and based on the structure of the FAQ there I would imagine they'd be eager to list any interesting other uses it would have, but no such entries exist there.
I would, however, also note that while DeepQA is IBM's proprietary implementation of QA using deep-learning methods, that approach is becoming more popular and is almost certainly being worked on by other companies and could soon be on other computers, if not already so in some form.
