Mental typing is definitely achievable, and there are several approaches to communications using the EPOC. The EmoKey application and several others like it allow the user to select letters or options using Mental Commands, Facial Expressions and gyro controls, and most of these packages allow control options to be restricted all the way back to Mental Commands-only for those with the least capabilities. This is an important area and there are new applications in development and popping out of the woodwork all the time.
Another approach to mental typing by thinking individual letters, using the P300 typing system can be realized with raw EEG data in real time. Two major real-time BCI research software packages now support the EPOC - these are OpenViBE (from India in France) and BCI2000 (from Wadsworth Center in USA). Both packages include a built-in P300 spelling system - this is a different method than Mental Commands to select items from a large panel of objects, and the implementation uses a keyboard layout with individual letters to be selected. With this approach, you are presented with a grid of letters where rows or columns are randomly flashed, and the letter you want is detected from lightly different responses when your desired letter is flashed. The process is not quick, but it can be remarkably accurate. It takes up to 25 seconds to select a letter but this definitely works even for locked-in users.
We are only just beginning to explore the potential applications of the vast array of BCI research which has been conducted already. It is fantastic that these packages support the EPOC and this will allow a much greater number of users to access this amazing research using an inexpensive and convenient system such as the EPOC.