Better Attributes

It would be nice, for a number of scenarios, to link attributes with products in some way. Typical scenarios of "User custom built products" would benefit.

Examples:

Custom computer -> Where you can configure a computer with different parts which are also sold in the store (they are already in the catalogue)

Custom bike
Custom travel package
Screencasts package
Books package
...

Essentially, you want the user to pick up some attributes, which info (name, description, picture(s), colors attributes...) have been already entered in the catalog. Attributes should allow this, in my opinion.

Re-entering that kind of info isn't nice and in Ubercart out of the box, for instance, attributes have only a couple of fields + price change + weight change. No picture, no description. So, besides the subproduct enhancement, plain text attributes (Size, color...) could benefit of the possibility of adding extra fields, enriching them.

This would totally rock.