To be honest, I wouldn't necessarily believe this story. There's still space for rent in that location, so my guess is that Amazon doesn't control the building just yet. On the other hand, I looked up Dion and according to the state of Deleware they first filed their incorporation paperwork in July - a bare 2 months before the merger. That looks like Amazon created a new sub in order to try to hide this purchase.
Now, I haven't managed to tie Dion's corporate officers to Amazon's employees, but that simply means they were careful this time to disguise the connection. I still think there's a real connection there.
So Amazon now own a speech-recognition startup. That's interesting, yes, but how do you think they'll use it? I wouldn't jump to any conclusions just yet. Yap had a consumer voicemail-to-text service in private beta, but that's only a taste of what they can do. A local Charlotte, NC tech blog believed that the underlying IP could do far more than just this one app.
Also, just because they bought a company doesn't mean they will actually use it on the Kindle platform. You might recall that back in February of last year Amazon got a lot of attention for buying a touchscreen startup called TouchCo. Everyone assumed that Amazon would use the tech in their next ereader, but they didn't. In fact, they still haven't used TouchCo's technology; the Kindle Touch, which is due out in a few weeks, uses an IR touchscreen from Neonode.
If I had to guess, I would bet that Amazon will use Yap to enable speech-recognition in one of their shopping apps before they use it on the Kindle. They'd want to make it easier for people to buy stuff because that's worth more than the Kindle.