what blogging sites are favorable to breaking new startup concepts?

That really depends on the concept. Different industries have different blogs covering new technology that's relevant for their readers.
For instance, my own startup is focused on real estate agents, so we got coverage with some of the top blogs that write about technology for real estate agents. That didn't take much work at all - because we have an innovative product that appeals to their audience.
In short, figure out what market you're targeting with your product, then figure out which blogs target the same market and approach them.

Why are you asking this question?

Is your underlying question: How do I promote my site to my target market? Or maybe your question is: How do I attract developers to my project?

You should state what you are trying to achieve, or it is difficult to give you guidance.

Hacker News would have to be my startup site of choice. Has a ton of good startup information and people willing to respond or comment on your idea/startup.