[BRIEF NOTE] Ottawan Sociolinguistics
Ottawa has long had a bilingual history. When I went in Ottawa's Terry Fox Centre in 1997, though, as much as I looked around the Terry Fox Centre in eastern Ottawa I didn't see much evidence of this bilingualism. Things were rather different this time, perhaps because I wandered more around central downtown Ottawa. My 1997 experience led me to compare Ottawa disfavourably to Moncton; this time, things went in the different direction. (There aren't many Francophone Maghrebin or African immigrants in Moncton, for instance, and rather fewer French-language signs.) It's interesting that this is so, not least because one-third of the populations of both the Ottawa-Hull and the Moncton Census Metropolitan Areas speak French as a first language, with half of both CMA population being bilingual.

The secret to this might lie in the uneven distribution of Francophones in the Ottawa CMA. This analysis of census data suggests that on the Québec side of the Ottawa river, 15.8% of the quarter-million residents were Anglophone, while on the Ontario side, a shade under 150 thousand of the eight hundred thousand Ottawans are Francophone. Aylmer on the Québec side is one-third Anglophone; Clarence-Rockland on the Ontario side is three-fifths Francophone, while Russell is part of a larger Francophone territory directly contiguous with Québec, and other enclaves assimilated into the city of Ottawa like Vanier (46% Francophone in 1996) also have significant Francophone populations.

Offhand, and without any conclusions which have been substantially backed up by scholarship, I'd say that there are four major differences between Ottawa and Moncton insofar as language use in their downtowns is concerned.
1. There are, in Ottawa's metropolitan area, large territories where Francophones predominate demographically (primarily the Québec side, secondarily enclaves on the Ontario side).
2. In the enclaves of the region's Francophone majority, legislative action (i.e. Québec's language laws) has given the French language greater status than a strict distribution of status according to demographic proportions would indicate.
3. There are simply many more Francophones living in greater Ottawa than in greater Moncton, and Ottawan francophones tend to be wealthier and better educated--hence, more resilient faced with assimilation--than their Monctonian counterparts.
4. Ottawa's an international city, on the frontier between English and French Canada. Somewhat like Montréal--and somewhat like Moncton's ideal--it's where the two major linguistic communities of Canada meet. This encounter includes the immigrants to both communities.

I just had to get this out of my system.