UPDATE : Since Dec 21 2012, this method didn't work :(
Now its not only for 10 years, but lifetime whatsapp License..
Just follow the tutorial from my ealier post.. if it's done n your license only for 10 years, just update your whatsapp via Playstore.
In update process, sms verification is needed. Whatsapp will send you a short message contain 6 digit code. Put the code to your phone, then check your license .... viola .. Now you get lifetime License
Note : This method only for Android gadget
If you dont have an iPhone, check my earlier post