No, I don't think that this trend will hold permanently. After a time this trend will decrease because a lot of people should recognize that they cannot cheat this way. Due to the fact that for a lot of people all these technology stuff is really new they don't understand the risk of these technologies.
I do think that technology is good in that people who are far away from each other can communicate now. It is important for military couples who spend months apart. You don't have to wait for letters to get mailed back and forth anymore.
People who live in the social media world can put their relationships in jeopardy. Especially if they sit there and put their entire business out for the world to see.
If we're talking about it taking our jobs each day passing... yeah, technology will eventually erase some of the humans on the Earth. It's a deliberate thing conducted by big corporations. We're 8 billion already, folks! How much can this Earth support anymore?
It can be a cause for long term relationships to end... but I think that if you are smart enough to know how to properly use social media it shouldn't be a problem for you! Sometimes people in social media are not discrete with their personal things, which could be a problem for their relationships.
Actually long term relationships are already over. Techonolgy has taken over our life in every way nowdays, I mean you can do whatever you want basically with just a smartphone: consulting maps, search for unkown terms, book tickets ofr bus/train, etc... I guess in a really few decades even the talk between people will be really rare to see.
I don't think that technology is the problem, I just think it's a vehicle that let's existing problems go faster. If a person cheats on their partner, there is almost always a reason behind it, and that reason isn't usually, "I can send her an instant text". Years ago, people world stay in this relationship for awhile until one got bored and started having lunch with another. Same problems caused it, same outcome, just a little slower paced without tech on our side. Smartphones don't make people cheat.