Uploading will not go directly to installed content. Upload is used for sending your new world to the Sims 3 Exchange (or for uploading objects, patterns, Sims etc.).
If you want to play your world you need to export it from CAW, then browse to the world file on your hardrive and double-click on the new world to install it. The next time you start a new game, you'll be able to select that world from the dropdown.