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. Digital art is just another tool in your arsenal. 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.
Learning and mastering digital art techniques and new software is one way to keep your skills and style developing in new directions. Working both traditionally and digitally can give you satisfaction and accomplishment in both areas and make you a more well rounded artist and illustrator.