Toss corn and asparagus in olive oil. Pre-heat grill to high heat. Grill corn on bbq until slightly charred (about 7 minutes). Set aside. Grill asparagus for about 2-3 minutes, until slightly tender and charred (but not overcooked).
Using a large bowl, stand ears of corn vertically in the bowl and slice off corn kernels. Cut asparagus into 1″ pieces. Add remaining vegetables, feta and oregano.
In a small bowl, whisk olive oil, vinegar, salt and pepper. Add to the salad and toss ingredients gently. Refrigerate for about 1 hour and serve.