I'm also a vegetarian and we just returned on Monday. We didn't eat at 1900 Park Fare but we did eat at Kona Cafe and they were very flexible with the menu. The only vegetarian appetizer on the menu was a salad and I didn't feel like having that so they made me an appetizer portion of the Vegetable Rice Bowl. I had the Pan Asian Pasta for my entree and they substituted tofu for the chicken or shrimp. Both dishes were excellent.
We also ate at the California Grill and I was very disappointed. We eat here every time we visit Disney because they serve a dish called the Vegetarian Unplugged which is usually outstanding. They serve 5 or 6 small portions of different vegetarian sides on the plate. In the past, each little portion was interesting, unique (without being too weird) and artfully presented. This time each thing was so ordinary - a spoonful of mashed potato, 2 small pieces of roasted potato, a spoonful of polenta with a few mushrooms on top, a tiny flatbread with onions and a few wilted greens. Boring. Definately a waste of 2 table service credits.
The Coral Reef has excellent vegetarian dishes. They had a creamy mushroom soup that had a vegetable base - it was a little peppery but delicious. For an entree they have a vegetable strudel that was sooo good. It's filled with lentils and vegetables and wrapped in a crispy, buttery pastry. It's served on a leek fondue that compliments the strudel perfectly. It comes with a piece of goat cheese on top but I had them leave that off.