Unified cart appearance - eliminate the cart page

@udig Have you made any progress on this yet?

Our customer has the exact same wish.

Looks like there's no easy way to update the quantity of just 1 cart item and re-use the AJAX functionality of the cart page for the cart block, as that requires a (Drupal generated) form to be present, containing the complete cart contents.

But we could extend the UcAjaxCart with similar functionality as there is for the item removal (from cart); removeItemFromCart().
Ps: codewise, removing an item from cart is the same as using the ubercart update function and setting quantity to 0.

The other "option" would be to re-use the cart page form to display in the cart block:
But that makes theming harder because of the tapir tables, as you already said.

My quick hack goes like this: add
$vars['form'] = drupal_get_form('uc_cart_view_form', $vars['items']);
to uc_ajax_cart_preprocess_uc_ajax_cart_block_content()
and replace the contents of uc_ajax_cart_block_content.tpl.php with

<div id="cart-form-pane"><?php print $form; ?></div>

Update:

I placed the preproccess extension, which provides $form to the template file, in a custom module to avoid hacking the core module as much as possible.
But I had to place ajaxCartInitCartView(); at the end of function ajaxCartInitCartBlock() in uc_ajax_cart.js to make it work.

I'm not pleased with the dirtiness of this hack.
But I am pleased with the result ;-)

Ps: I used a hook_tapir_table_alter() implementation and some CSS for visual cleanup.

Another update:

To fix the fact that this doesn't quite work until the page gets refreshed, a module hack is necessary.

I removed drupal_add_js(array('uc_ajax_cart' => array('AJAXIFY_CART_PAGE' => TRUE)), 'setting'); from uc_ajax_cart_form_alter() and placed 'AJAXIFY_CART_PAGE' => variable_get('uc_ajax_cart_ajaxify_cart_page', 1), in _uc_ajax_cart_load_res() so the javascript setting is also available on non-cart pages (showing the cart block with ajaxified cart page functionality).

And I added drupal_add_css(drupal_get_path('module', 'uc_cart') .'/uc_cart.css'); to _uc_ajax_cart_load_res() so the default cart (page) CSS also gets loaded on every page.

Can you please add a zip or rar with the final stuff ?