Airbnb has recently started providing selected hosts with much more details with regards to the reviews that they receive. In addition to showing the % of reviews that are 5-star, hosts can now see a breakdown of the actual ratings per category.
This information can be really useful for hosts who are looking to improve their guest experience, as they will now be able to pinpoint where they can improve. Instead of seeing just the average over all ratings, an actual rating count is provided.
Airbnb provides these insights for all the different categories. In addition, they also show the average five-star rating in the neighborhood, so hosts can see how they are doing compared to their peers.
Airbnb is providing hosts with lots of new functionalities this year, as promised at the Airbnb Open in November 2014. They are certainly delivering. Other updates that have already come out are increased calendar functionality, the Airbnb pricing calculator and the dashboard upgrade.
The next step would be for them to release the names of the reviewers that left a sub-par rating. This would enable hosts to reach out to the guest and ask for feedback. I don't expect that this will happen though, as Airbnb is very keen on protecting the privacy of their users.