"Perfecting the Saints" is rather general and non-descript. It does include charity and caring for the needy, but it's lost amid many other places where the body of the Church needs polish.

Making "Care for the Needy" a separate pillar emphasizes that this is a major, separate endeavor that is requires extra attention more than ascribed with just the general "Perfect the Saints". It also emphasizes that all needy need our care, not just LDS needy, and encourages people to do more than just a fast offering.

I think it's great. One of the major attributes of Zion is that "[all things are in common]" among them. The Church and the body of the Saints must become ready to live the United Order and consecrate all of their property into the hands of their respective bishops; we must become more supportive of our needy or impoverished brethren temporally and spiritually.

This addition indicates to the mind of the body of the Saints that they must do more to help their needy brethren and that the Church's programs and instructions will assist in the facilitation of these endeavors. I think it is good, and that is an important part of the preparation of the people to come to Zion.