The SRU have agreed a five-year deal with the governing body to stage the final leg of the competition at Murrayfield on June 2 and 3 next year.
SRU chief executive Gordon McKie said: "This really is excellent news for Scotland and for sport.
"Our priority has always been to win the event for Scotland.
"We can now showcase the international appeal of seven-a-side rugby and hopefully attract many more young Scots to our sport."
But the SRU are still hoping to stage the World Series at Melrose beyond 2007.
McKie added: "It is fairly well known we have been keen to take the event to Melrose, where sevens began, and especially for its anniversary year in 2008.
"Unfortunately, we were unable to conclude the necessary financial arrangements with the relevant authorities in the Scottish Borders in time to enable the staging of the IRB tournament there in 2007.
"It is important to note, however, that we have secured the event for Scotland and we remain willing to explore the Melrose option for some date in the future.
"If this is not possible, and, if it makes sense, we will also be prepared to examine the merits of taking the sevens event to other parts of Scotland other than Murrayfield, after 2007."