Yes, definitely do something, do not forget about the little tyke. For some reason he came to your window, and you've shown you care by looking for and finding him. Get some kitten food, and the box with the blanket would be a good start too. Once the kitten knows it can get food from you, it will probably start trusting you, and if you can keep Tommy Earl calm, the kitten will probably venture indoors, especially if it's cold and nasty outside.

Please let us know what happens.

PS - as you can see, I'm partial to black cats, so I'd really like to see this little one rescued.