I was listening to a Leonard Lopate podcast (Thanks, Eric!) on dialects. Experts actually say that improved communication and technology hasn't lessened the number of different dialects, nor does it look like the number will be hindered much in the future. Pretty much the opposite of what one would expect (or at least, what I expected).
Technology has affected very isolated dialects, but only to some extent. In particular, some words no longer used in daily life have disappeared, as technology shapes every day life. For example, we don't churn butter, or chop wood, or live on farms much, so the varied words linked with these tasks have lessened.
Here's the link:
http://www.wnyc.org/shows/lopate/epi...9#segment72255