Update 12/21: The PlusBox is now visible in FireFox and Safari on the Mac
Matt Cutts recently wrote of a New Google UI feature: Plus Box. Several things interest me about this announcement:

First and foremost it is another push of local data out the main Google search window. This will continue to make Google Maps data more accessible to the average user and do so in a way that doesn’t disrupt the clean Google interface. This is consistent with previous Google behavior and my ideas about their long term strategy that I noted in the past.

It is also of interest on several tactical levels. Firstly, the feature which Matt noted on December 9th is still not available to everybody. When I search on Matt’s search phrase I do not get the “Plus Box” (but I am happy to have a name for it). Apparently this is due to the fact that is currently only working on IE and will soon be available for Safari, Firefox Mac and Opera.

In the past I have noted several times when an authoritative local search returned an expanded Plus Box. Recently though I have not seen this behavior. Was it just an interface experiment or will it occasionally still show up on an authoritative local search result on the organic page?