On a somewhat related topic, the Metro Centre had revenue of $7,165,956 for the fiscal year ending on March 31, 2010. It was down from $8,530,335 for the previous year ending on March 31, 2009 (source:
http://www.tradecentrelimited.com/site-t...20Halifax%20Metro%20Centre%202009-10.pdf). The reason for the decrease was because the IIHF World Hockey Championship was held in 2008 (the year ending on March 31, 2009).
The WTCC I convention centre had direct revenue of $6.883 million for the year ending March 31, 2011 (source: "Convention Bump Whittles TCL Shortfall, Brian Flinn", August 9th edition, allovascotia.com).
I think those are impressive revenue numbers for the two venues mentioned. One difficulty with deciding on a design for a stadium is uncertainty in estimating yearly revenue. Personally, I think it will be quite successful, but it doesn't have the revenue history of the Metro Centre or WTCC to mitigate any financial risk.