CBS News has learned exclusively that Prince William's girlfriend, Kate Middleton, has been.
And that, veteran royals watchers agree, could put William and Kate a significant step closer to the altar, and be the biggest hint to date that wedding bells may be just around the corner.
Some say it's not a question of if, just when.
The last truly gala royal wedding was 30 years ago, notes CBS News Correspondent Elizabeth Palmer, when William's father, Prince Charles, married his mother, Lady Diana Spencer.
Now, the country is waiting for an encore.
Kate and William met while attending university in 2003 and, as a couple, became fixtures on London's club scene. More recently, says Palmer, "The tone of their public appearances has become more, well, sober. And their intentions apparently serious."
In fact, over the past year, while William finished his training as a search and rescue helicopter pilot, he's been sharing both his house and his life with Kate, Palmer notes.
How soon will the arrangement be made official? British bookies say 2011 will definitely be the year, and the smart money is on June.
But royals expert Neil Sean says he sees late summer as a more likely time "for the simple reason," he told "The Early Show on Saturday Morning" co-anchor Rebecca Jarvis, "(that), if you check the royal diary (calendar), you can work out exactly where Prince William may be. And certainly, we know that Kate Middleton does have some gaps in that diary. You know, rather cruelly, people do call her 'Waity Katie' over here. But she is a modern woman and the bottom line is, at 29 or 28, or whatever years old, does it really matter that she's not married quite yet? She's already proven that she's got her man; they are engaged without the official moment. So, obviously for them, she kind of sees her life together with the man she loves, Prince William."
"This is a brand-new version of the royal family," Sean says. "We have Prince William and Kate Middleton living together with the Queen's blessing. That's totally different in royal circles. And when you get an invite from the Queen to spend Christmas, the festive season, with her, which by the way is her favorite season of the year, how would you dare say 'No?" '
Sean added that quiet is generally the operative word for royal Christmases. "A lot of people sort of expect that it's going to be like a scene out of 'Dallas' or 'Dynasty," he told Jarvis. "It's actually quite a subdued affair. They play party games. … They watch TV (only) after 6:00 in the evening, once all the meal's gone. But it's very much a sort of tranquil setting. The Queen is very religious and likes to take this time of year to reflect on everything that's gone on and maybe look toward the future, and the future is, of course, a royal wedding."