As long as I'm around they will never be obsolete.

A blonde walked into a library one day, walked up to the librarian and said, "could I please have a hamburger, fries and a Coke?"...the librarian looked at her and said, "ma'am, this is a library..."...and so the blonde leaned over and whispered very quietly, " oh I am sorry, could a please get a hamburger, fries and a Coke.."

Nothing like a good ole hardcover book.

I have worked full-time as well as volunteered as an assistant librarian. The function of a library is not becoming obsolete because of the internet. It supplements the Internet and makes it more powerful. The Internet is very powerful in searching and finding specific items. However, it is very lousy at browsing. So that's where the library shines. Most patrons know how to find a particular subject of interest on the shelf in a library. But in searching for that title on the shelf, they come upon many subjects that they had no idea about but interests them too. There is so much more to a library than just books.

Librarys have internet, silly. ;P
But for real, print's independence of electricity will give it some longevity.

Libraries will still be used by people who can't or don't want to buy books.