I am going for intiial testing with Navacanada soon (I am a Canadian and a Brit, but lived in Canada all my life), and I have spent a fair time poking around their websites as well as many sites such as this. I have also done a tower visit, and met with one of the main tower control trainers. Here is what I have taken from all these sources:
NavCanada is in a bit of a weird situation right now. When they were a government organization, they had a huge hiring binge between 1965 and 1975. As a result, out of the 2200 or so controllers, many of them are coming up on retirement. This is particularly true in the towers, somewhat less so in the IFR but still an issue. The percentage of employees over 55 is fairly high in some of the centers. Say again Over can surely comment on this.
At the tower I visited, they were looking at over 50% retirements in the next 5 years, and often sooner (because of an interesting buyout deal to get people to leave... which is sort of weird).
If you check the NavCanada business plan (2005-2008) they make a very VERY vague reference to this issue, but it was indicated to me to be a much bigger issue than they let on. Further, it was indicated to me that the ability to train is being outstripped by the demand. In the most recent labor contract, training of new IFR staff has been moved from Cornwall Ontario directly to the centers themselves. Some people suggest this is to open up more space so that more VFR controllers can be trained at that facility (more classes).
2005 saw 70 or so new IFR, and 2006 was set for over 200 IFR students. There was no indications for 2007, but it appeared to be on an up curve. Apparently the IFR centers in Winnipeg and Edmonton are still somewhat understaffed, and while NavCan states they are at 105% staffing, the reality in the field seems to be that overtime is there for the asking because of fairly clear shortages in some areas.
As Say Again Over mentioned, if you want to work in Quebec, well, you need to be at bare minimum spoken word bilingual (english french), with reading near the top as well. Montreal and Quebec City are both nice places to live and relatively cheap (when compared to Toronto, Vancouver, or the current stupid housing situation in Calgary), but that requirement makes it more difficult. It should be pointed out that because the requirement is to be fluent in english to work at NavCanada, they appear to have a harder time getting recruits out of Quebec.
If you are looking to cross over, check out their website and follow the deal. The timing will only get better in the next 24 months, as the retirement bump pushed NavCanada to take bigger steps to fill their gaps.
Alex