A new camera is on its way which is capable of recording in high definition (HDV). In January, recordings will begin in high def., and for a while both high def. and standard quality versions of movies will be available. If there are no problems with the high def. versions, we'll eventually transition to these only.
At the moment, I have no idea how much bigger the files will be, but they will inevitably be larger. This also means prices will increase to compensate - each time you buy a movie via Files Forever, we are charged a download fee of around $1 for each 400 MB. This is likely to be the magnitude of the increase in most cases.
The size increase may also impact the availability of movie sets if the collected (zipped) file sizes exceed 2 GB, the Files Forever limit for a single file. I will experiment with various quality levels to try to reach an acceptable balance between picture clarity and file size. I shall post more information when I have more information.