Sure it's still possible. People still frequently play text-based MMO's, and even MUD's. You're not gonna' appeal to a crowd of WoW fanatics, but if the content is well thought out, you could appeal to a niche crowd.
Sometimes, text based MMORPG's are so boring, but it was a good experience since I was a teenager. Oh man, I can't believe until now more people are addicted to it rather than flash games?