The TYPO3 packages has not yet been submitted to packagist, we want to make sure that everything is working as expected - including the recent name changes, before going official. we do however have our own composer repository available at http://ci.typo3.robertlemke.net/job/composer-packages/ws/repository/packages.json. And http://jul.net/packages.json can be used as a shorthand for that.
so what you can do already now is this:
composer.phar create-project --repository-url="http://jul.net" typo3/flow-base-distribution TYPO3-Flow
or put this in in your composer root-manifest:
"repositories": [
{
"type": "composer",
"url": "http://jul.net"
}
],