I think that what you have described about cyclical interest in reading is much more common than those who constantly are reading. There are so many activities and obligations and distractions in life, both good and bad!
In the past, I went long periods of time without reading except where necessary, and manuals/tech books/etc. But when I discovered e-books on my handheld, and then now on my Sony Reader, I found that it makes it more fun to read so I do it more. It combines my love of reading with my love of gadgets in a very practical way, and it also makes the whole thing easier on my eyes also. At the risk of offending e-ink fans, I'd have to say that my Treo LCD screen is even easier on my eyes than paper.
Actually, for me, in order of hardest on eyes to easiest on eyes, I guess it's...
CRT monitor -> LCD monitor -> paper -> Treo LCD -> e-ink
I'm sure that is different for everyone.
Plus, most of us probably agree that reading is a good use of time, so the Reader is actually something that pulls me toward a positive activity. In the reverse direction, TV is not generally an enriching activity. So I have my living room arranged specifically so that I don't
end up watching TV every time I sit down, but only shows I specifically intend to watch.
Don't get me wrong... I don't know what is best for you, so I wouldn't try to persuade you to get a dedicated reader device if it's not right for you. But I found your topic interesting and just wanted to share my thoughts on it.