Apparently the team behind Bump brought their app into bars and tested it on drunk people.
A bar is more representative of the environment in which a mass market app operates [...] Drunk people are maybe a good approximation of distracted people
Source: Fast Company, Why You Should Test Your App On Drunk People
I would say that considering people who are impaired or intoxicated is always useful. I think the implication is quite clear: if impaired persons are able to use an interface with ease, then unimpaired persons should also find it easy to use.
There are a few examples of interfaces which are used by a high number of drunk people. Pub quiz machines and karaoke machines spring to mind. In these cases, it is imperative that the interface at least considers the effects of drunkenness (e.g. blurred vision, poor hand-eye coordination, etc).