Very Nice!
Please think about tweaking the Checkout Button. You have the price showing in the button and on my iPhone I see the price and "Chec...". This will be confusing for some of our customers.
Using
http://www.mdemo.x-cart.com/
Desktop --> full size template
iPad --> mobile template
iPhone --> mobile template
Initially the popup allows you to switch between the templates until you say dismiss. It would be nice to have a link to manually switch between templates in case you change your mind later.
We've gone full circle in our thinking between a separate mobile template vs a responsive template. I like responsive templates and I'm currently converting 2 of our Wordpress sites to new responsive templates.
For our store we're very happy x-cart went with a separate mobile template. Our site has a lot of CMS, and other features which work great on a desktop but for our mobile shoppers we want something that's quick and easy for them to navigate and make purchases.
Great job and looking forward to purchasing soon!