I have noticed the same thing occuring.
I often update my models with newer versions before ordering, so the auto-emptying cart was a nice feature. The main reason I would put them in the cart was to get pricing for non-default materials, but that is no longer necessary with the new interface.
Another reason I would put items in the basket and later not want them later is that the part models get updated with small tweaks before becoming ready to order. But now it appears that one can update an item with new data rather than creating a new item, so that reason also goes away.
Last edited: Nov 28, 2011