I'd use some of it to make Turkey Tetrazzini. Cooking Light has a great recipe, http://www.myrecipes.com/recipe/turkey-tetrazzini-10000000405641/, that tastes even better the next day.

Take one of those big bags and have a pasta party! Get your friends to bring a salad, bread and dessert. You make the pasta and a sauce and/or get friends to bring a sauce, some red, some white some other kinds.
With the other bags, remember, you don't have to cook the whole bag at once. There are two in my household and I usually cook 4 oz of pasta for us. It makes two or three meals. I think you could spread the other three bags over the year....fall with roasted veg, fall apples and brown butter sage sauce, winter with red or white meaty sauce, spring with spring veg and maybe chicken and summer with a shrimp olive oil sauce or the freshest tomatoes and basil you can find for a fresh sauce.
Good luck with your windfall

if its dried it should keep ok for at least a year if stored right. My first thought was also to host some people, share your bag(s) of pasta!

you have some great ideas here!
can i also say, what a lovely gift in the first place. the way to catherine's heart must be through her stomach! how wonderful.

I've had this on my pinterest board for ages, yet I've never been able to find tagliatelle at any of my local stores. If you end up trying it, let me know if you like it! :)

http://duonosirzaidimu.wordpress.com/2010/03/12/tagliatelle-su-avinzirniais-ir-sauleje-dziovintais-pomidorais/

Thanks for the great ideas, everyone! And yes, the way to my heart is definitely by buying me surprise pasta :-) I particularly love the idea of a pasta party, pasta with apples and brown butter sage sauce, and jessws61's recommendation of pasta with chickpeas and sundried tomatoes. I have a feeling it may not take us long to finish up these bags of tagliatelle after all!

I do an herb tagliatelle thats fantastic: toss one pound of the cooked pasta with 1 tablespoon butter, 1 tablespoon chopped chives, 1 tablespoon chopped parsley, 1 clove of garlic (grated on a microplane), and sea salt and freshly cracked pepper to taste.

The pasta can be eaten alone or it is delicious with many different types of sauces on top: bolaganese, stroganoff, beef stew, etc.