You need to focus. The e-mail you posted here is well written, but too generic to make an impact nowadays. You need to tailor your story to fit the sources you're most interested in. You will not get coverage on even three of the sites you mention, since they're all keen to get exclusives, so don't bother with the mass mails. Foster some relationships.
Look at the blogs you're targeting. Really look. Your e-mail provides no story - it asks me to come up with one and try to fit you in to it. This distinction is important, especially for Mashable, RWW, and LifeHacker. Go through their stories and look for patterns. On RWW you'll see a mix of "news" about well established companies and "how to" type stuff often featuring smaller companies (like yours). Mashable is very list and "soft" news oriented (note posts about Justin Bieber, dating, and "happiness." LifeHacker is very "how to" based.
Your story is basically "news" but it's not a "story." You need to seed the bloggers who are looking for stories (like the above three) with stories, not release news.
(I could write a lot about this but I've been up ages and need to get a few hours sleep before going to the in-laws.. I hope you can sympathize.. :-) Any questions, ask away and I'll be back later.)