If you believe it or not, Tacitus had a huge impact on Christianity. He not only explained the existence of Jesus Christ, but he also described the torture of Christians and Jesus's crucifiction. Tacitus did suggest that Nero used the Christians as scapegoats. Various theories have been claimed since then as well.
Yes, Tacitus confirms the existence of Jesus Christ, because he made non-Biblical references to Jesus. His histories were meant to begin with the death of Augustus in 14 AD. This is during Jesus' time, and Tacitus confirmations of these historical events are a good reference to non-Biblical proof of Jesus' existence.
Most people would not quarrel with the fact that, based on ancient texts, there was a historical man named Jesus who was a wandering teacher and healer. What is in question here is what Jesus claimed about himself and if he is different in some qualitative way from any other gifted person who teaches and heals.
No one has ever actually confirmed the existence of Jesus Christ. We simply have to believe what the bible says. Even if there was a Jesus Christ, he did not do all of the things that was said in the bible, they are just stories passed down through generations to us.
Given that Tacitus was not writing directly at the time of Jesus Christ I do not believe The Annals confirm his existence. For me, I have no problem believing that Jesus Christ actually existed. As much of the story goes he was a carpenter turned preacher who ended up with a decent following. It's the resurrection and his direct connection to God that most people have a hard time with.