There will always be a need for illustrations done with traditional materials BUT you should know how to scan and color correct your own work, and send sketches via email. It also helps if you have some knowledge of digital illustration for making changes on final artwork. It is becoming more important to understand the basics of digital illustration and how to prepare your files for publication as many publishers are expecting these skills from their illustrators.
I personally feel that every illustrator needs to be trained first in traditional materials and techniques. Then if you choose to further your studies in digital painting you will already have the basic skills you need to transfer to a new medium. Traditional training will also allow you to keep working in case of a technical disaster.
You need find a happy medium that lets you work in a method and style that works for you but still keep abreast of the rapidly changing face of technology in illustration today.