I just de-glazed my new All Clad pan after frying up some chicken breasts. I was not sure how to get the pan clean so I de-glazed it with water. Should I keep that for making broth or something or just throw it out?/
Yes, you can save it. I transfer it to a small container, label it (with the date), and stick it in the freezer. At some point in the future I'll rediscover it and add it to broth, soup, or a sauce. (Generally, the advice is 6 to 12 months, during which time it loses flavor rather than becoming a health risk. I've used it safely long after that.)
Most of the time, of course, you'll use it to make a sauce for the dish you're cooking. But if you don't use it now, it's a generic meaty-brown flavor that pairs well with a wide variety of things. You could throw it in a pan with sauteeing vegetables, or on top of sauteed scallops, or add it to beans.
You could also refrigerate it; use it within 5 days.