A story on the CBC news web site has the title, "Canadian shipbuilders fear navy will buy German vessels." The headline is misleading. Sources tell the CBC that the navy's replenishment ships may be replaced using a German design, the Berlin class, even though the construction would be done at Canadian shipyards. The contract is worth $3 billion. According to the story, "in recent years, the German industry has lobbied the Canadian government to supply designs for frigates, destroyers and new submarines."
If the Germans succeed, then they might offer the new F125 class frigates, which are about the size of destroyers (7,200 tonnes) and noticeably bigger than Canada's present destroyers. Germany will commission its F125's between 2016 and 2018.
The submarine design offered might be the Type 212 (1,830 tonnes, submerged), which displaces a little less than the current Victoria class submarines (2,455 tonnes), has about the same sized crew, but is 13 m shorter. Since the current boats will be thirty years old in 2020, Canada might put the replacement out to tender in 2015 or so.
Correction: the export version of the Type 212 is the Type 214.
Update (28 June 2013): In fact, the rumours were at least partially right. The Berlin Class design will, in fact, be Canada's new "Joint Support Ship."
I think that the frigate or destroyer design is more likely to be one that is original to Canada, as the existing frigates are, than a German (or British, or French). That is not to say that they will be primarily designed in Canada, considering how much of the design work is being outsourced to Denmark and the United States.
As for the submarine fleet, well, we'll just have to see. If we hadn't bought the British boats, we very possibly wouldn't have any submarines at all. On the other hand, if Harper is still the PM in 2015, he'll still be dragging around a poor reputation for military procurement and might not want to open another can of that type of worm.
Nuclear-powered submarines, by the way, are still the only sensible ones for a nation that wants to send them into the frozen north. The debate about getting them will reopen when parliament starts to talk about submarines again, but I have no hope that Canada will buy a quartet of Virginia or Astute or Barracuda class nuclear submarines. Despite Mr. Harper's efforts to get Canadians thinking of themselves as warriors, they have no stomach for rearmament during peacetime.
So, in short, if we do order new submarines, the German Type 214 is probably going to be in the short list of candidates.