Dtrain has a summary of Hayden's appearances on Australian TV during his recent promotional trip:

Free to air TV have had numerous appearances with stand outs being Channel Ten's Rove Live which featured not only an interview with the "Dark Lord" but he also participated in the show's comedic celebrity charades routine (where he had to guess a whole lot of Australianisms as part of his routine - poor guy!).

Channel Nine's Today show also hosted a 5 minute interview previewing Revenge of the Sith, incorporating footage from Episodes 2, 3, 4 and 5 to explain the back story. Presenter Richard Wilson also interviewed Hayden. Hayden's answers in all his interviews thus far have repeated George Lucas' comments that Anakin's fall to the dark side is the result of making a "pact with the devil" and that Anakin's motivations are strongly related to his inability to deal with inner conflicts.

Clonetrooper has more on his Rove Live appearance:

He spoke about how lucky he was to wear the vader suit and how hard it was to move cause he couldn't see through the mask very well. We even saw a bit of the cinema trailer, and after it ended, we saw Hayden cross his arms at Rove as they continued to talk about the film.

After a short break, we saw Hayden looking like he was going to punch Peter on Rove Live in the back room, and then he competed against Peter in a quiz game. At first he didn't know what his female partner was trying to tell him, cause his partner had to tell him the words in body language, and he had to guess, but couldn't. But when it was his go to do the body language, he did a very good job and did about 6 words. The last was a cigar and he was funny by doing this.

And here are more Australian articles that reported on his trip. Click on the links below to read more. Thanks to Jessica for the alert:

AAP:

HOLLYWOOD actor Hayden Christensen summoned as much of the Jedi force as he could muster tonight, becoming the first person to put his hand print in Sydney's Fox Studios Star Walk.

Attending a premiere for his new film Star Wars Episode III - Revenge of the Sith, Christensen at first had trouble making an impression in the wet cement.

So he enlisted his bodyguard to help push his hand down.

The Australian:

HAYDEN Christensen loves the new Star Wars film in which his character turns to the dark side.
At least he thinks so - the Canadian actor still hasn't seen the finished movie.

"It's a little weird," he said of promoting something he hasn't seen in full, and which won't be released worldwide until May 19.

"But it's also sort of fitting, because it's so shrouded in secrecy that not having seen the film makes it easier not to give away all the plot points.

"But I'm very eager and excited to see it. (And) it's the one that I think everyone's been waiting for. It's for the real diehard fans.

"It's going to really pay off in a sense that it ties into the original trilogy in such a smart, gratifying way, so I'm very excited for this film to come out."

Sydney Morning Herald:

So what was it like donning the famous helmet for the first time?

"It was just one of those ecstatic moments," he said before the trailer screening. "Just the sensation of having it on was very empowering and just really cool."

But on exactly what makes the young Anakin turn into Darth Vader, Christensen was guarded: "I can't give away too much. But Anakin is a very conflicted character, a very complex character, and I think struggles with the frustrations of life and those anxieties get the better of him in this film.

"He makes a pact with the devil, in a way."