IMHO, people (and hence language) will always adapt in certain ways to get the message across. People already learned how to "google" and expect the same style of search queries to be effective elsewhere. When speaking on the telephone, people tend to slightly change their voice to counteract the channel noise (with acoustic consequences such as increased fundamental frequency ["pitch"], etc.). I would be surprised if a similar adaptation didn't happen for human-computer voice interaction, which would ultimately help making it work well enough to be useful. (Of course, using speech recognition to transcribe human-to-human interaction will still be barely usable..)