Totemists are essentially melee combatents. If you look through their meld lists, most of their abilities focus on doing damage with natural weapons. That said, they're not a one trick pony by a long shot.
One thing totemists do VERY well IMO is the scout role. Many of their melds pump up traditional scout skills such as spot and listen, and the ever popular Move Silent and Hide. They can gain darkvision, tremorsense, blindsight, and Scent. They can gain Track without taking the feat, as well as get bonuses to Survival checks. They can get cold or heat endurance.
While most of them are higher level, you can gain a wide variety of AoE attacks, mostly in the form of breath weapons. Related, you can gain a wide variety of energy resistance and even SR.
Best of all, a totemist can be very unpredictable. As a player, you can have, literally, a completely different array of attacks and abilities without having to buy/sell a lot of equipment. As an opponent, they make good recurring villains as the PCs will have a hard time narrowing down how they're going to be attacked. On a related note, since you're most likely not pumping all your funds into better weapons, you can concentrate it in other areas, leaving you a bit more well rounded when it comes to equiping yourself.
There's also the potential humor value in running around, trying to stab people with your "Attack of the Purple Worm!' and its milky white poison, but then I run around with what can be an immature group, so your mileage may vary.
