Nope, not twins. Just a single baby, no womb-mate! The child will be next in line for the throne following Prince William.
The palace released this statement today about the royal pregnancy:
"Their Royal Highnesses The Duke and Duchess of Cambridge are delighted to confirm they are expecting a baby in July."
A July due date means the baby could share a birthday month with the late Princess Diana...and me! The palace also confirmed Kate Middleton's extreme morning sickness is improving!