Yes, the resurrection of the KGB means a lot for Russia and the rest of the world because it is one of the most powerful institutions across the world. The fact that the KGB is coming back should alert every politician because it shows a resurgence of Russia's old policies.
The resurrection of the KGB could be good for some of the Russian elite and could be bad for the general population. If the new KGB is just as large and powerful as its predecessor, I'd generally guess that it's not a such a good thing for the US, especially with all the talk of hacking and potential interference with the upcoming election.
The KGB, it should be remembered, was not a traditional security service in the Western sense — that is, an agency charged with protecting the interests of a country and its citizens. Its primary task was protecting the regime. Its activities included hunting down spies and dissidents and supervising media, sports, and even the church. It ran operations both inside and outside the country, but in both spheres the main task was always to protect the interests of whoever currently resided in the Kremlin. With this new agency, we’re seeing a return to form — one that’s been a long time in the making.
The resurrection of the KGB is a return to the police state and it will change the way Russian interacts with other countries. It is likely the return of a very dark period in history. With the new technology available, Russians will have no privacy and it will be much like the novel 1984.