Scenario: On your website, you have products that each have fields for Name and Color, in addition to price and some other fields. You want to create an Association (Multi) on another section of your site (say, the blog) that allows you to tag Products that are relevant to that particular post.
The Problem used to be: Only one field could be set as title, so it was impossible to see whether you were tagging the Red Doll or the Blue Doll.
Solution: Titles of collection entries can now be built from multiple fields. Simply select all the fields you'd like, and the full title will be built automatically for you. This will affect autogenerated Permalinks as well.
Let us know if you have any questions!