How long has this "Homecoming" thing been going on?
As far as I know, the Year of the Homecoming 2009 was initially intended as a one off but proved so successful that there was a desire to repeat it in 2014.
Off topic but (money ) Do you think that the http://www.london2012.com/

this year will help the econumy in Scottland any ? I hope so
The London Olympics are perceived here in Scotland as very much an English event. The organisers obviously see it this way as the Olympic Torch only makes a brief cursory visit to Scotland and does not even call to visit us here in Hawick despite this being an important tourist destination as the main gateway town of the Scottish Borders, Scotland's Heritage Capital and the Home of Scottish Knitwear. However I would expect that the London Olympics would indirectly benefit Scottish tourism as many people who would visit London from overseas for the Olympics would take the opportunity to also visit Scotland.