I find it funny that they make an announcement that they're going to make an announcement. Personally I think it wont be anything TOO surprising. Probably more confirmation that there used to be or is water on it. It's kinda always been plausible so while confirmation is good it's not anything out of this wor... Wait, I guess it is.
Now what would be really cool is if they found fossils of actual multi cellular organisms or perhaps some abundant minerals like iron, carbon, sillicon etc that would actually make it plausible to build there. Basically if you can establish a small dome where you can grow stuff and live, and have access to all those minerals so you can mine them, then you can continue to build more domes and buildings to build and establish further. Downside of such a colony though would be that you are depending 100% on man made structures to even survive.