This month, the Chicken Marinara Melt will give way to the Western Egg & Cheese as Subway's $5 featured footlong. As far as the AZFoodDude can tell, the "Western" Egg & Cheese is the same as the Black Forest Ham, Egg & Cheese. That sandwich comes with ham, cheese, veggies (green peppers and red onions recommended), your choice of egg or egg whites and is shown on flatbread or an English muffin.
In terms of nutrition, you can check out this Subway site and calculate how many calories, fat, protein, etc. will be in the sandwich based on how you want the sandwich made, egg or egg whites, for example.