An exception might be if you have a very similar announcement. Doing so would get you included in the same articles as your competitor.
Wait, what? Why would Google view the WhatsApp news as competitive? Other than it setting an insane price and inflating bubbles more, how is the FB acquisition really useful news to anyone?
This tech will have far more impact on the world. Apart from the few people doing startups, FB buying WhatsApp will have almost zero impact in day-to-day lives.
I was only responding in the context of parent's PR comment, re: scale of press worthiness of the day. Tech sites have been covering WhatsApp/FB non-stop for the past 24 hrs.
As for impact on the world, this is just a call for developers. I'm encouraged by the ambition, but it's too hard to judge if this will be successful. FB/WhatsApp will almost immediately affect 400M users (+1M more per day).