Today, I am announcing an announement

It is time for an end to the "I am writing to you today to announce...." or the "Today, I am announcing..." intro. Please make your announcement, tell us how great it is and how our lives will be better now that your product/service/idea is out there.

With every company CEO, gov't official, and home-based scientist announcing something on a daily basis this starter has run its course.

Your announcement is (hopefully) important and worthwhile - don't hide behind a tired trope.