SevenCubed - 10:15 pm on Nov 29, 2012 (gmt 0)
If I'm understanding the OP correctly then you should be considering microformats(.)org VS schema(.)org for structured data markup. I doubt meta head tags are worth anything now. I'm assuming you are referring to head meta tags as opposed to either of the 2 I mentioned?
A very basic primer: Those two streams of structured data presentation were sort of in competition to each other, just sort of, it wasn't a big war. Schema org appears to be the standard adopted by Google and Bing going forward. The geo info you want to implement is of course supported in the schema stream. They are a sub-set of meta tags.
The Drawbacks: schema org markup is only valid in HTML5. If you are using a DOCTYPE less than 5 you will need to go with microformats org but I don't know how much support the search engines have for it.
I just rolled out my first HTML5 site 3 days ago. The only reason I strayed away from my XHTML 1.1 preference was so I could use the schema markup. Google had the site index page in SERP less than 24 hours later (on page 1) and was using the rich text snippets from the schema markup as the description. Bing doesn't have it indexed yet.
Here's an example of what a markup might be for a local business...
<div itemscope itemtype="http://schema.org/localBusiness">
<div itemprop="name">Rudolph Enterprises</div>
<div itemprop="contactPoint">Santa Claus</div>
<div itemprop="address" itemscope itemtype="http://schema.org/PostalAddress">
<span itemprop="streetAddress">343 High Point</span>
<span itemprop="addressLocality">Arctic Circle</span>
<span itemprop="postalCode">H0H 0H0</span>
<div itemprop="geo" itemscope itemtype="http://schema.org/GeoCoordinates">
<meta itemprop="latitude" content="77.777777" />
<meta itemprop="longitude" content="-77.777777" />
The nice thing about the above is that you can use the meta itemprop tags right in the body instead of the head and they are perfectly well acceptable to the search engine, validator, yet remain hidden from users (just the meta tagged ones).