The importance of user reviews and rating in YLocal (and all most other Locals properties) has been discussed in the past. User review/ratings play into the algo for YLocal and have the other obvious benefits associated with them.
Here is yet another reason to pay attention to your (your customers) user rating on YLocal.
(Note: This change has been place for a bit, but I don't believe it's been discussed here.)
On www.yahoo.com, if you conduct a local search that triggers the YLocal result set to appear in the above the standard SERP set (e.g. "restaurant in somemajorUScity") you'll notice that if a star rating is stored for the local business profile in YLocal, Y is pulling that star ratings into the SERP display.
This is significant for a number of reasons, but the biggest is the prominence of these red stars on the SERP page along with the high volume of people still conducting explicitly local queries on the Y proper site as compared to the Y local site.
If you compare the local.yahoo.com display for the same search, those same top three results arguably do not have the same draw on the page that they do in Y proper SERP. In YLocal there is a lot more activity on the page competing for attention, more local results that just the top three, additional methods for navigation/sorting, etc.
In the Yahoo.com SERP, there is much less going on. The red stars draw the userís eye; in fact the red stars are arguably the most drawing items on the page especially given the top placement.
The upside: A savvy person can dominate for traditionally pretty competitive queries as well as see large CTR on the listing.
The downside: A bad star rating could kill your chances before someone even bothered to look at you.
It's the same argument that has been preached before with regard to the importance of a user review/rating strategy, this type of implementation just ups the ante for what it can do for you.