Casey Meraz has published on the JurisDigital blog the first eye and click study on the new 3-pack for local results in Google.
The key findings were that "organic was the clear leader with the #1 organic result generating 39.5% of total clicks." Adding that "while 39.5% of the click-throughs on the organic result went to the firm’s website directly, only 6% of the local clicks resulted in one click visits to the firm’s website."
Here is the click data:
Here is an eye tracking heat map with the new 3-pack:
This is a significant change to the local results, so understanding searcher behavior here is helpful.
Forum discussion at Local Search Forums.