Can really Opencart come up with the real One-Page checkout with Enhance user friendliness rather than the Default JavaScript based Drop downs with real One page professional integrating it to the next Level with the Highest conversion rates as the following steps still need to click them for the next rather the Concept of One-page checkout gets completely diluted still customer has to click mouse 7 times to get thru the final order confirmation making it the Beta Version for Opencart one page checkout.
Step 1: Checkout Options --- Click Number 1
Step 2: Account & Billing Details -- Click Number 2
Step 3: Delivery Details -- Click Number 3
Step 4: Delivery Method --- Click Number 4
Step 5: Payment Method ---- Click Number 5
Step 6: Confirm Order ---- Click Number 6
Confirm Order Final Click Number 7
Why Not put all the details nicely and well professional in one page clearly visible all the details Next to Computer screen making the customer aware they are really on final step for Order way rather than confusing or taking more time for clicks.
Few Examples but some of the best Open-source True One page integration
http://www.one-pagecheckout.com/images/gal_img1.jpg -- The best and well professional (8/10) -- its called single page check-out
http://www.onepage-checkout.com/picsmain/enlarge.html -- (7/10)
More Conversion, More customer friendly Lesser hassle Free and greater Shopping Experience

I hope the New Updates will be quick Fix on New Truly One page Checkout rather than multi-layered 7 clicks keep clicking checkout in Opencart 1.5.x
Many thanks Regards