2.1 of the cart system is now in development. You can follow its progress at:
This version sees a few major changes. The frontend interface has had a complete facelift and the admin area some minor changes, mainly to the menu. 2.1 also sees better support for additional gateways and I will be adding new gateways for this release.
I have a large feedback list, so I`m working my way through seeing what is do-able for this version, so check the progress page for confirmation of updates.
More info when its near completion.