Serena Williams revealed that she plans to compete in the 2012 Olympics.

Women’s tennis without the Williams sisters ?  It’s something which seems unimaginable after the way in which both Venus and Serena have dominated the game and become global sporting icons over the past decade.

However over the past couple of years there has begun to be speculation about how long they will continue to play on for. Both are approaching 30, which really is old age nowadays on the WTA tour and both have multiple interests outside tennis and various flourishing business ventures.

There is more doubt about Venus who has been struggling for form at times this year and apart from at Wimbledon, she now tends to make little impact in the slams.

However luckily Venus and Serena doesn’t seem to have plans to quit anytime soon. One of the few trophies Serena hasn’t obtained in tennis is that precious Olympic gold medal in the women’s singles. She has won two golds in the doubles (in 2000 and 2008) but the memories of her quarter-final defeat to Elena Dementieva in Beijing still rankles.

“2012's just around the corner," says Serena. "Venus and I are so going to be there. We are already talking about how exciting that will be on grass. What a great moment. But I could have won the singles last time. I was up 4-1 against the girl who went on to win it with an easy shot to go 5-1. And I lost."

So we have at least three more seasons to appreciate the Williams sisters. One of Serena’s aims is to overtake Billie Jean King in the lists of grand slams won. If she continues to show the unstoppable form she displayed in Doha last week it will be a formality.