I'm not sure if this is what you're looking for but here are my thoughts:
For us, I think we're going to stick to "reading, writing, arithmetic," for the elementary years, too. I plan on working in history through reading Bible stories, the Little House on the Prairie series--essentially first-hand accounts of what it was like to be in that time period. For science, we will grow a garden, go on nature walks, get field guides, and have a couple of fun science experiment books to do every now and then. We also live near some cool science museums. As for everything else, it will come up as it comes up, like geology might be discussed as we look for fossils among rocks. We might find a good book about constellations at the library and take it home to read for astronomy. Dh and I are trained vocalists, so music is just part of our lives. We sing a lot and for dd this is just commonplace. As dd gets older we will start some instrumental training when she can read and feels she's ready. Art is something we do informally right now but I like the Waldorf approach to teaching Form Drawing and Wax Sculpting in the early years so we'll be doing that, as well as visiting art museums. Geography comes from our own travels. We act out stories and go see plays, so drama also fits in. We plan on getting dd involved in gymnastics or ballet and a choir as extra-curricular activities, so that takes care of phys. ed., music, and foreign languages (you'd be surprised how many languages you can learn about in a good children's chorus). I guess my point is that probably a list isn't going to be all that helpful--just do lots of fun things. From your list, you obviously know what the basic categories are for being well-rounded. You'll cover the 3 R's formally, so try and find fun family things to do that explore all of the other.
I personally think the best way is just to look for ways of having fun together as a family and to aim for experiences that are as 3-dimensional as possible. So, in my opinion, a trip to a Renaissance Faire is far preferable to reading a book about ancient Greece. I think at this age just "living" in a world full of fun and adventure is education enough. And a parent's enthusiasm about a particular topic is quite contagious and accounts for a lot.
