That's the magic question - it seems somewhat subjective. And seems to depend on the bias of who gives the estimate.
Best thing to do is look at the actual spec's. Metrolinx released a document last year that had the dimensions of the existing CLRV, ALRV, and the new LRVs for the legacy streetcars, and Transit City:
http://stevemunro.ca/wp-content/uploads/2010/06/LRV-Fact-Sheet.pdf
The length's seem a bit wonky (list 24 metres for ALRV, while TTC uses 23 metres - and has the Flexities at 28 metres and 31 metres, while TTC is using 30 metres), but it also gives the widths. 2.54 metres for all, except 2.65 for the Transit City LRV.
Assuming the TTC lengths are correct, and the Metrolinx widths are correct, then a CLRV has an area of (assuming it's a rectangle) of 38 m², an ALRV has 58 m², a legacy Flexity has 76 m², and a Transit City Flexity has 80 m².
Reported CLRV capacities are 102 normal, and 132 crushed (from
Transit Toronto, and ALRV is 155 normal and 205 crush.
Scaling this, the Transit City LRV would have a capacity of 212 normal and 277 crush. (and the new legacy LRVs would be 203 normal and 266 crush - this is similiar to the 260 number being bounced around last year).
Conservatively then, I'd say the crush load is 270 per car on Eglinton (about 800 per train).
What has been ordered in Ottawa? This seems quite low - lower than a Toronto ALRV. Hmm, sounds like a Toronto ALRV ... used?