Bundles is the new Ravelry feature that I am very very excited about. From what I can see, it will make both the designer's and the knitter's life easier: you can bundle projects grouping them by category, yarn weight, simply to highlight a specific technique, or even to present a new pattern collection or a sale. It eliminates the search to a degree making pattern browsing within the designer's page easier and giving the designer the option to feature their patterns in a whole range of ways.
At the moment it is only available to designers, but from what I understand they are planning to make it available on other places of the site. Exciting beginnings! Care to share what you think or how you'd use it? I'm curious to know :-)