At the end of episode 2 is the scene that I find people either love or hate. Yoda pulling out his lightsaber and fighting Count Dooku. Personally, it makes me wonder how much we can really believe Yoda. He is a very wise little dude, and I have to wonder how often he does not tell the whole truth, or maybe only pretends not to see things.
For example, he is small. As we learn in episode 5 however, we should not judge him by his size. He is much stronger than he appears. Yet he walks slowly, with limp, and is often seen with a cane. His battle with Dooku shows his tremendous strength and talent, yet he hobbles away on his cane as though a weak crippled old man.
Earlier in the movie, when he talks to Palpatine, he and Mace Windu share some glances that make you wonder how much Yoda at least really knows, but isn't willing to share. Now I'm not saying he knows who Palpatine truly is, or that Anakin will turn, but he can sense that the dark side of the force is very prevalent around Palpatine. They say as much in episode 3.
As we watch episode 3, even more of Yoda's strength is revealed to the audience. Specifically in his fight with Emperor Palpatine, aka Darth Sidious. Yoda is able to completely fight off all of the Palpatine's attacks.
So, how trustwothy is Yoda?