DogeCoin has already succeeded.

In 5 days, it has
- 11 pools (and these are just the ones I know)
- A large trading community
- An exchange
- Casinos
- Multiple IRC channels with ~100 participants
- An active an large custom forum
- Top 8 highest hash rate of all scrypt coins

People are exchanging them for items all over, see http://doges.org/index.php?board=18.0