Let's think this through.
If it's just other life - microbial - this might come as a surprise to some, but honestly, the universe is so big, it's bound to happen. What's it mean for us in the long run? Eh, does it really matter? It'll mean that the next step is more likely, but given the odds already ...
Technological life - eg life that has altered its planet's atmosphere enough that we can detect it using standard astrophysics. Well, this is interesting, but unless we can contact them, it doesn't mean much.
Technological life that can communicate with us - This becomes more interesting, for obvious reasons. Is it bound by the rules of physics we know now? Or, like in *Contact*, can the aliens actually communicate instantaneously (in contact, via Einstein-Rosen bridge, wormholes, which are theoretically possible now, but the science is far from settled. I mean, GR still has closed timelike curves possible, and I doubt a unified theory would allow such paradoxes to exist).
If they can communicate with us, it's a question of how long/how fast. Current physics, or will a unified field theory allow something faster, say something *instant*? How does that change the game?
Worst case - their intentions are bad. Or they have good intentions, and don't know how to establish contact without risking a huge fuck up. Game over for Earth, and really, there's nothing we could do about it, could we.
Best case. They know *exactly* what they are doing, their intentions are not only good - minimize harm and suffering, maximize freedom and happiness - but they know *exactly* how to pull it off. What does this look like? What would it truly mean to have the best case for first contact? Contact hints at this - small steps, and the ultimate question is "how? How did you manage to survive?"
Turns out if you run this in your head logically, the answer pops right the fuck out, and I suggest you do that now, then we can compare notes.