The data portal contains all of Statistics Canada's CANSIM data, as well as data from the Department of Finance, Health Canada, Environment Canada, Transport Canada, Citizen and Immigration Canada, and so on.
To try out the data portal, I gave it a couple of tests.
First, I searched for government revenue. There are two bodies that produce government revenue data - Statistics Canada, and the Department of Finance. Unfortunately Statistics Canada does not produce a consistent, long-term series of government revenue data. For example, the current on-going series, 385-0032, only goes back to 1991.
The Department of Finance does produce such a series in the fiscal reference tables, but those tables aren't something that a person would find unless he knew they were there and was looking for them.
Data.gc.ca contains both Statistics Canada's CANSIM series, and the Department of Finance's fiscal reference tables. Unfortunately, when I did an unrestricted search for "government revenue" the fiscal reference tables only started to show up in the fourth page of hits. The download, once I got to the right place, was very easy, but only gave me data up to 2010. The Department of Finance web site currently has data up to 2011 available.
It is possible to search the open data portal by specific department, and in future I may well search everything except for Statistics Canada, so my results aren't dominated by pages of CANSIM series. If I want CANSIM, I'll go to Statistics Canada directly - the strength of the data portal is that it allows me to search all of the other government departments.
One thing that is exciting about the data portal is the availability of geo-spatial data. I tested that part of the site by searching for "Rideau River." Nothing came up. So I tried Ottawa. The first hit was for Paleo-environmental records of climate change across Canada - Vegetation History, Glaciated North America - I didn't try a download, but it looked like an amazing resource.
The current data portal is a pilot project. I doubt that it will ever be as shiny and glossy as the World Bank data portal, http://data.worldbank.org/, but it could incorporate some of the World Bank portal's features. For example, I would like to be able to search for micro data (or meso, e.g. community or region-level data) separately from time series data. Sure, the micro data search might only spit out the census, but it would be a start.
The data portal could also learn from commercial sites such as youtube. One of the major problems with the data.gc.ca site, as with the CANSIM site, is that there are so many series, and the most useful series do not always rank highly in search results. Allowing users to flag the most useful series, and keeping track of downloads, would be a way to improve the quality of the search results.
I'm not a serious data person. Someone who was might have other suggestions. For example, how about giving data sets DOIs, those things at the end of academic citations, e.g. DOI:10.1126/science.7716547, that mark the permanent web home of the article?
These are my thoughts, but take it for a spin, and drive it yourself. The best way to ensure that the open access initiative is maintained, supported, and expanded is to use the data.