It's unfortunate, but I think it's great to see a company take a proactive approach to something like this.

The ideal situation would of course be that no-one ever got in, but they may have, and Dreamhost have owned up to that right away and fixed things (hopefully!) before any damage occurred.

That's not a bad attitude for a company to have I think. Can't have been an easy call for them to make, especially when they can't really have been certain of what had happened!