At present, using the "products list" CMS block, you can diplay products from the same category, in a block ... however, display products in a CMS block from ANOTHER category, is proving to be a little more difficult.
 
E.g. if you want to display products in a custom CMS block (using the products_list.php as the script source for it), it is almost impossible as there is no way to set the current_category variable (have tried settind the category_id too but it won't budge)!
 
What I am trying to do is display a number of CMS blocks on the homepage, each containing the featured items from the different categories of the site - has anyone managed to do this and if so, please tell me how! :)