I don't think it has anything to do with blog or being a blog, in my opinion (and its just that) you are seeing a drop due to the local aspect.
Blue Widits My City
We are heavy into the local scene as well and unless you have a physical street, phone, address... that will lead you into the Google Places directory, you probably just got bumped to +8th position minimum.
We are seeing local 7-pack for queries that used to provide traffic... and could easily provide general web traffic, but its like Google has taken it upon itself to try and fix the US economy, and turn on some local mojo, spawning more local results.
I suggest getting as many local signals onto your site as you can...
- Add your local phone number - Add your local address - Claim your Google places page
If you don't actually have a physical local address... well, I don't know what to suggest. Its ONLY MY OPINION, but I think local serp's (cityname + short or longtail query) are going through a pretty big change right now, putting the focus on brick and mortar businesses. (aka a Brand Signal)