If you’re wondering: “Wasn’t Queen Street all ripped up about two years ago?” and “Why are they doing it again?” this looks like the answer (from the TTC’s page on the project):
“Work to replace the watermain, combined sewer and streetcar tracks on Queen Street East from Greenwood Avenue to Coxwell Avenue, and on Connaught Avenue between Queen Street and Eastern Avenue will begin on May 7 and continue to November 2012. Sidewalk improvements and road resurfacing are also included in this project as part of a comprehensive approach to maintaining street and service infrastructure. This work builds upon the watermain construction work that was carried out by the City during summer 2010 on Queen Street East between Woodfield Road and Coxwell Avenue.”
So it builds on the watermain work that was done before – not entirely clear as to what that means. But you are right if you think it was all disrupted not very long ago – it was just two years ago.