Siri is “one of the most popular features of our most popular phone” according to Apple CEO Tim Cook. But: “There’s more that it can do”. Cook also noted that for some people, Siri has become their “best friend”. (We think he may be confusing the episode of Big Bang Theory where Raj started ‘dating’ Siri.)

Speaking at D10, Cook told told Kara Swisher and Walt Mossberg: “Customers love it. It’s one of the most popular features of our most popular phone. But there’s more that it can do.”

The company is investing time developing Siri and Cook thinks consumers will be “really pleased” with some of the things that are in the pipeline. Cook said: “We have a lot of people working on this. And I think you’ll be really pleased with some of the things that you’ll see in the coming months… we’ve got some cool ideas about what Siri can do. And so we have a lot going on this.”

He added: “I think Siri’s proven that people want to relate to the phone in a different way. For a lot of years, there wasn’t a lot of invention in the input. Touch came along, and that was cool… And voice, when it understands the context… voice recognition has been around a long time, but what makes Siri cool is that she has a personality. She becomes many people’s best friend.”

If it all sounds a bit si-fi, it is. “This is something that people dreamed of for years, I think. And it’s here. It’s really here. Now yes, it can be broader, and so forth, but we see unbelievable potential here. And Siri as a feature, it has moved into the mainstream. People hear the word Siri and they know what you’re talking about. So I think you’re going to be really happy with where it’s going. We’re doubling down on it.”

Siri is Apple’s voice-recognition ‘PA’ feature on iPhones that has come under fire recently in a series of lawsuits that claim Siri doesn’t work as advertised. Siri was tagged as beta when Apple launched the iPhone 4S, and yet the company still picked it as the lead feature in its advertisements for the new phone.

Steve Jobs would have “lost his mind over Siri,” according to an ex Apple employee. And a developer has said that Apple had to release Siri as a beta product, but what they shouldn’t have done is marketed it as “magical”