Some people maybe have already noticed: I am not as active any more at the TYPO3 scene. The reason is quite simple because I concentrate more on another topic called Magento.
Magento is a new ecommerce platform which is also open-source. There are dozens of impressive features and no TYPO3-shop-extension can beat Magento. Right now I develop a new shop which has been once developed with TYPO3 (3.5) and a very old version of tt_products.
Out of this reason I wrote another extension to import products and customers from tt_products to a temporary table which can afterwards be imported by Magento.
The extension doesn't work out of the box and you need to adopt it to your needs!