I would like the ability to populate an attribute list on the fly in the Add 2
Cart template.

The existing attribute system would be perfect, except the error checking done
to make sure the value is legal.

I want to attach an attribute list so I can process it during Post Gateway
Complete of the Orders module.

This would work the same as it does now, except you only define the attribute
name but not the attribute options.

Example:
$players = array  containing Name/SKU pairs.

{Cart productid=foo action=add2cart attrib1=$players  }