Assuming it's true (like NASA isn't lying to deceive us or trying to get our hopes up or anything), and assuming they could be habitable, I'd hope that faster-than-light travel could exist soon. The fact that there's seven Earth-like ones in one system is pretty awesome.
Although since they're much closer to their star it has me wonder if life (let alone us humans) could live on them without frying our eyeballs. They can't be sure if they're Earth-like enough yet aside from size and distance.
Big assumption that NASA (never a straight answer) is telling even a kernel of truth, I think there are philosophically bounded parameters we have to meet in order to visit and play in our celestial backyard.
1) We would need to be a planet of people, not a bunch of different nations existing and fighting each other for resources. When every human is designated as human (not [insert racial/cultural/national moniker here],) then that begins the first step.
2) We need to become a "warp" society. In other words, we need to
publically, and globally be at a point at which we can drive ships at, or very near the speed of light. The technology exists now, but it isn't for public consumption. The world would have to be "warp," not just the respective black op branches of governments.
3. The entire planet would need to have their energy needs met such that poverty, hunger, homelessness and other pitiful states are nearly nonexistent. This exists now, also - but free energies are not for public consumption yet. We are still under oil delusion.
4) Once we are "warp," or near warp, we would need to be able to demonstrate a clear understanding of periodic activity in our solar system. In other words, our science would have to take a gargantuan leap to reflect a mastery of understanding of our own "backyard."
5) We would need planetary defense systems. Again, we have this already, but it need to have global consciousness of existence attached to it. Collective consciousness is important in interstellar travel.
6) The integrity of our species must take a gargantuan leap - or we will need to make sure we can build our technology at a pace that inversely matches our failures in our species (and, therefore intergalactic diplomacy.)
7) We will need to understand dimensional travel on a fundamental basis. Again, we know about it but it isn't something all people on this planet even believes exists. One theoretical way to travel FTL is to "grease" the boundary of a ship with exotic matter, and send it through a dimensional bridge (the exotic matter lubricates the friction of the space, LT, and FTL travel - as well as isolates the ship in an exotic stasis so that there are no mass and energy problems.)
8) If we get to 70% of those things, we will likely be visited by other entities first before we take our first real trip. Now, some would argue that other entities have already visited throughout the history of time. For example, I believe most UFOs people see are actually reverse engineered technology from terrestrial governments.
We would have a long way to go before we reach FTL on a
consumer knowledge basis.
Technically, FTL isnt as effective as dimensional jumps (warp is technically a tesseract of space-time, not FTL travelling for the ship.) Dimensional jumps allow mass to go great distances by making ER bridges lubricated with "exotic matter."