Tumblr makes it very easy to jump right in. There are hundreds of themes, I found a decent enough one within a few minutes.
I recommend going the Tumblr way first, mainly to get over the inertia of setting a blog up. This is the biggest hurdle that stops you. Get into the habit of writing a blog first, then later you can choose another tool that you prefer once you have developed your own blogging style and you know your likes and dislikes a bit better.
I have used WordPress for a non-technical blog for over 3 years now without any issues. I've also been thinking about starting a technical blog and have been looking into using Drupal for it.
That's, of course, assuming that such an announcement is made in the first place. Last year the timthumb bug was being exploited and not all theme download sites bothered to alert the users that the themes were vulnerable.
Ah, I remember reading about the timthumb bug at work and checking right away when I got home if my site was vulnerable to it (which it wasn't).