Looking for meal-planning / grocery list software
Disclaimer: I am the owner of the company behind this service as well as the programmer of it.

Except for calculating nutritional data, http://bechamel.net does exactly this, if you are a registered user (which is free). Please note that there's not a whole lot of activity on the rest of the site though, and because of that, there's not a lot of development going on (that doesn't mean there are any plans to shut it down, there's not). 

To use Béchamel for this, go to a recipe, click "I want to eat this soon", drag the recipe to the applicable day, go to the shopping list, and add the recipe. You can adjust servings either per recipe in the list, or globally in your profile. It will even coalesce equivalent ingredients in the shopping list (2 eggs in one recipe and 3 eggs in another will become 5 eggs in the shopping list).

Feel free to use it if it fits your needs.