I'm kind of a heavy user, ship a few hundred packages per month, I use open cart, as a large volume package handler, here is the features I feel are extremely important to me... I know you guys are always wanting to think up some cool new features, but how about some to simple features that make everyday tasks in opencart less daunting? (no offense intended, I think you guys do a great job)
1) Ability to bulk update tracking numbers, and have opencart parse tracking numbers, and figure out appropriate hyperlinks to email the customers, with custom email message. http://forum.opencart.com/viewtopic.php?f=110&t=35584
2) Printable invoices for customers, similar to how we print invoices in the admin, it does not have to be PDF, in fact it would be best if it was not, just plain HTML would be fine, just something they can click "print invoice" and it looks like the one we print.
3) Ability to track profit loss, as a business, the ability to enter my cost for an item, and the cost it sells for, and have a chart or graph I can view monthly, weekly, quarterly, yearly, stats for that would be extremely beneficial.
Also more detailed stat's in the Reports section would be nice. At a minimum Products purchased needs to have date sorting and grouping like the sales report has, currently 'products purchased' is kind of useless (no offense). I'd much rather know how many of a product I sold in a month, week, quarter, or year, not since I installed open cart.
4) My code for flate rate box calculating would be nice to have already added in to open cart, a lot of people like this feature: http://forum.opencart.com/viewtopic.php?f=114&t=11096
5) A quick button from the dashboard to view pending orders that need packaged and shipped, instead of having to click "sales->orders" select the pending order filter, and click the filter button.
6) Force customers to only be able to select the lowest cost shipping option when a 'Free Shipping' coupon is used.
....some other features which would be userful....
5) Ability to make only specific items visible to specific customer groups, or all customer groups. Reason is, you may have a ReSeller for some of your products, and when that reseller log's in, you only want them to see the item's they can buy from you at their reseller discount rate (aka wholesale rate)
5) Under "sales->orders" in the Action column, have [Print] [View], so you can print the invoice without having to click view first.