What is wrong with voice recognition technology?

Hello everyone,
I have to do a presentation about one of the latest technologies such as RFID, wii and natal, LED TV, etc.. I've chosen voice recognition as my presentation topic; however our professor has asked us to find a problem with the thing we chose and then propose a solution for the problem and I don't know what to do with it. can you please help me with the task at hand by suggesting what problem might be there and how can we fix it? Also, if you think the topic I chose is not that good please help me choose another topic that you find suitable for such a task.

Thanks

What is wrong with voice recognition technology?