I found this in the Guardian Book blog:
Two years ago, I had a very straightforward reading pattern. Every few days, I'd read a book. I would immerse myself in its characters and storylines, swim in its style, snatch every opportunity throughout the day to return to its enveloping world. Then I would finish it, and start another one.
Things were so simple then.
I wish I could blame it on the Christmas eReader, but my evolution into schizophrenic multimedia literature butterfly started long before it landed in my lap – via iPod and Audible, Twitter and Gutenberg, and brick-like new-writing magazines that take weeks to digest. My reading has taken on a strangely driven, guilty quality, as I try to justify the cost of all those subscriptions and all that hardware by consuming fiction in an unprecedentedly multiplicitous and simultaneous way. Secretly, I long to return to a world in which I had a loving, stable relationship with one paperback at a time.
To answer the question, my reading habits probably have changed, but I don't see it as a problem. To be more specific, my discretionary reading has changed. But since in this instance I'm reading for enjoyment, not to accomplish a specific goal, I really don't see the problem.
I'm looking at this from the historical perspective. The ways in which people enjoy themselves (and the ways in which they learn) change with technology. People adapt themselves to new ways of absorbing information. Is it good or bad? Well, that's a matter of opinion. Does it work? is really the only question that should be asked.