OPTIONS:
For something Minestrone-ish, you could add another cup of tomatoes, 1 Tablespoon of Italian herbs, a can of beans, and a little pasta.
For Tortilla soup-ish flavor, you could add 2 teaspoons cumin, 1 Tablespoon oregano, 1 bay leaf, half a bell pepper chopped, some chopped cilantro, and a few good squeezes of fresh lime.