Place rotini, vegetable stock, milk, honey, garlic, salt and pepper in large stockpot. Bring mixture to low simmer over medium heat, stirring regularly. Simmer until rotini is cooked al dente. Reduce heat to lowest setting; stir in balsamic vinegar and 3 cheeses.
Stir until cheeses have completely melted and mixture has thickened, about 3 minutes. Remove from heat and mix in cherry tomatoes, sun-dried tomatoes, basil and arugula. Salt and pepper to taste and serve immediately.