Well, I don't know what you mean by 'horn being tooted for a long time'.
Information about Expression of Interest has always been available, I guess you don't know where to look (immigration.ca/en/immigrationnewsarticles-menu/152-canada-immigration-news-articles/2014/april/738-express-entry-immigration-program-to-launch-in-2015.html).
Though the Canadian government has repeatedly said the model is being worked out, see below for some more details:
The Canadian Government plans to launch a new immigration system that would offer express entry to qualified immigrants for filling open jobs for which there are no available Canadian workers in 2015.
Named Express Entry – formerly referred to as Expression of Interest – this program would provide swifter entry into Canada, wherein the government and employers would select immigrants based on the skills and attributes that Canada needs. Canada's new immigration system would come into force from January 01, 2015. Under this system, prospective immigrants would apply to express their interest in coming to Canada by answering a series of questions about their professional skills, their education, languages spoken etc.
The system would then match the skills of the prospective immigrants with the labour requirements identified by the provinces, the territories and employers.
Immigration Minister Chris Alexander said that Canadian employers would be able to bring workers into Canada through the Express Entry system, with the long-term objective of making them stay behind in Canada. In a press conference, he said, "You can bring your labour market opinion, your job offer, to the Express Entry system and ensure that the person you need comes to Canada as an immigrant, not as a temporary foreign worker. Not as someone who is here with an uncertain future and likely to go back, but as a full immigrant to Canada".
Alexander said that prospective immigrants who apply via the Provincial Nominee Program could also benefit under this system as long as the concerned province and territory brought their program under the federal one. Immigration authorities would extend invitations to Express Entry candidates for applying for permanent residence if they have a valid job offer or a provincial or territorial nomination.
Other features of the Express Entry program include the fact that Canada would be able to select the best candidates, who would be able to achieve success in Canada, rather than just the next person in the queue. Immigration authorities would also have access to an improved Job Bank for matching Canadian employers with the most suitable Express Entry Candidates.
The Government plans to invest $14 million over two years and $4.7 million thereafter, to ensure that Express Entry is a success.
Source: CBC News