I hadn't seen the Godfather Part 1 for about a month until tonight...and as I was watching it, the scene in the garden (where Vito tells Michael about the traitor) struck me. Was Vito actual worried about Michael's future??? IT seemed to me that he kept repeting everything. At one point Michael even asks him "what are you worried about? I'll handle it"

From this scene, I think Vito was worried...and was scared for Michael's as well as the Family's future. Vito regrets how he wanted to give Michael a better life, and now I think he's scared.

As it turns out, this scene is tremendous as it shows the true intelligence of Vito. We not only able to see how Vito actually figures out how the opposing Families are going to come after Michael, but he also somewhat foreshadows the ending to the entire trilogy. In the garden, Vito asks Michael "Are you happy?" I think if you were to ask that same question to Michael at the end of Godfather Part 3, he would obviously say no. He lost everything. He lost his daughter, Mary. I forget the quote that Michael says, but its soemthing about how children are the true treasure in our lives...

What do you guys think?

Yes he was worried because michael was his favorite son, though he had full trust in him.
Plus he was getting old, so he might have become forgetful and was repeating stuff.
When michael says he can handle, i think he was referring to killing carlo.
And I agree with you that vito displayed great intelligence in the scene. It was as though his instinct was not dulled by his old age.

Great topic!
I think that Vito in that age was in the reflecting sort of life phase, and tried to figure whether or not Mike would get through it then with things were changing.
I believe that he had no doubt at all for Mike, he was the smartest and tactical son afterall. Vito just wanted to make sure. He was sure of Mike getting alright handling the crime family.
As for the natural family, I think Vito was worried more, because Kay was not an Italian and would never accepted this "Sicilian thing" ... Kay would never want to handle the family in their traditional way.

sure he was worried and scared about his son. he wanted something else for michael, like you said a better life as he had. i think you see it very well in this scene.

I'm sure Vito was worried about Michael's plans for revenge, etc., as any father would be worried about his son's future.

I think Vito repeating everything, though, was meant to illustrate that he was perhaps becoming a bit forgetful in his old age, and that he was just a shell of his former self.

This served to strengthen in the viewer's eye the necessity of Michael taking over.

Certainly he was worried and concerned about Michael's safety. But his caution also was by way of apologizing to Michael for having put him in harm's way. "I never wanted this for you..."