The singer, who became an international star after wowing the judges on Britain’s Got Talent, told them to “watch this space” for more announcements.
She said: “There are plans in operation for that, but that’s for later on.”
It comes as One Chance - the biopic of Paul Potts, who also achieved fame after appearing on BGT - was released with James Corden in the lead role.
Boyle was speaking at a central London press conference to announce the release of her Christmas single - a duet of O Come, All Ye Faithful with Elvis Presley.
All royalties from the song will go to Save The Children.
Boyle, who described it as “awe-inspiring” to sing with one of her childhood heroes, said: “Duetting with Elvis was beyond my wildest dreams. And now that this is able to raise money and help children is simply fantastic.”
The singer, who has become an ambassador for the charity, filmed the video for the track at a Glasgow primary school.
She said: “I’ve had the privilege of spending time with families from a Fast programme - Families And Schools Together - that is run at a school in Glasgow. To see the money raised in action and the difference it makes to these families is wonderful. It really does help people.
“The children from the Fast programme also joined me for the music video. We had a lovely two days and the children were fabulous. They were all stars.”
The single, from Boyle’s fifth album, will be released on Sunday December 8.
In a recorded message to a central London press conference, music supremo Simon Cowell said he was “proud” of the star.
He said: “No-one of all the people I’ve met has a bigger heart than you”.
The charity’s chief executive, Justin Forsyth, said he hoped the song would “highlight the plight of children around the world”.