It's a big year at Hogwarts - and not just because "Harry Potter and the Half-Blood Prince" marks the last time the series will be set there.

Harry learns more than ever what it is to change from a pupil to a soldier. "The big change for Harry this year is his relationship with Dumbledore (Michael Gambon). Previously [it's] always been teacher and student, and this year it changes to being a general with his favorite lieutenant," says Daniel Radcliffe, who has long played the lead part, during a press conference in New York today (July 9).

"It was a great opportunity to dive a little bit deeper into Draco's head and discover that he really is a coward, through-and-through," says Tom Felton, who plays Harry's sinister nemesis.

Hermione Grainger gets a chance to put the books down and feel the effects of her crush on Ron Weasley. "In the other films, you've seen quite a strong Hermione... but in this one you see a very different Hermione," explains Emma Watson. "She's much more fragile, emotional and vulnerable. She's experiencing her first heartache. It was a challenge for me."

As for Ron Weasley... Well, Ron gets a break in a few ways. "I like to think this is Ron's best year at Hogwart's. He gets a girlfriend, joins the Quidditch team for the first time," beams Rupert Grint.

Indeed, romance plays a larger role in this dark, character-centered "Harry Potter" flick, with tension building and releasing with a kiss between Harry and Ron's sister, Ginny (Bonnie Wright). "Poor Bonnie...My God, my lips are like the lips of a horse. Distendening independently away from my face and trying to encompass the lower half of hers," Radcliffe railed as he described re-watching the scene, as Wright shook her head and laughed at the other end of the table.

But it's not all teenage love and bravado. "The Half-Blood Prince" also has a fair share of mystery, firepower, Death Eaters, loss, lies and, of course spells and elixirs. One crowning moment is when Harry drinks a vial of luck potion and shows off a spazzier character.

"I just let the more manic side of myself that I suppress for 23 hours a day loose on set. The uncontrollable, vaguely irritating, vaguely amusing person that I keep hidden. It is a side to the character that hasn't been seen before," Radcliffe says.

"I think drugged Harry is closer to Dan's real personality," Watson happily adds.

The film is set to hit theaters July 15, but the actors, director David Yates, screenwriter Steve Kloves and producers David Heyman and David Barron are already knees-deep into the final installment of the Harry Potter series. "Harry Potter and the Deathly Hollows" will be released as two separate movies, the first set for release in fall 2010 and the second in the summer of 2011.

"The seventh book is such a long book, there's almost nothing you can cut out. All of us made the decision - and the studio was rather happy about it - that we should do two films," says Yates.

And what may keep fans abuzz until that time comes is the much bally-hoed smooch between Ron and Hermione. That scene was filmed a mere two weeks ago.

"Rupert and I felt the pressure of this kiss...This is 10 years worth of tension and hormones and chemistry and everything in one moment, and we had to ace it. I'm sure you'll critique it... please be nice!" says Watson.

As for Grint's recent bout with swine flu, he's all better, thanks. "You're fine," he assures the members of the press in the room.

"Harry Potter and the Half-Blood Prince" opens nationwide on July 15.