The council say they are thinking about the local taxpayers, having a Premiership rugby club in the city. Yeah that's nice, but football dwarves rugby union anywhere across the country, and the money and prestige is far greater. Having even a Championship level football club is worth more in terms of footfall and interest, and slightly less in prestige (Wasps are a European-level side traditionally).
This also has a big impact on Coventry RFC, who were one of the leading union sides in the 70s and 80s (a bit like a rugby union version of Leeds or Forest in League 1).
With the Ricoh sponsorship up in 2015 I expect Wasps will have all their own deals in place and colour schemes for the stadium. It'll be back to feeling like an outcast, but at least the team will still be in Coventry (for the short term).