What is behind Twitter's mysterious tweet?

BANGALORE, INDIA: On Thursday evening, Evan Williams, the co-founder of the micro-blogging site Twitter, unleashed a storm of rumours with just a tweet.

"Tomorrow just became a very big day. (Sorry for the teaser - more later)," his 70-odd character tweet read.

The moment it appeared on Twitter, there were interpretations and rumours from many corners – while some interpreted it could be a big announcement, others felt it could be something related to Evan's personal life.

What could be the possible announcement? It could be that talk queen Oprah Winfrey is starting to use Twitter from Friday.

According to news reports, the megastar talk show host plans to send her first "tweet," on the hot micro-blogging service on "The Oprah Winfrey Show" on Friday.

Within hours of Oprah announcing the creation of her Twitter account, @oprah, on her Facebook page on Thursday, it attracted more than 36,000 followers.

Oprah has also said that the guest on her show on Friday would be the man she described as the "King of Twitter" - Hollywood actor Ashton Kutcher.

Recently Twitter was in news following the rumour that Google may buy the microblogging site. Then came the news of CNN taking control of the popular Twitter account CNNbrk, which is being handled by London-based developer James Cox.

And now this mysterious tweet has once again made news. And there are people like Dan Frommer from Silicon Alley Insider, who believes the announcement could be totally personal. “Is Even telling us something about his personal life - perhaps a development in his wife’s pregnancy?” he asked.

Anyhow, a less-than-140-character tweet is enough for Twitter to unleash a wind for Twitter, it is for sure.

But do you think the 'mysterious' tweet is a hype to be in the media limelight?