At current growth rates Metro Vancouver will hit the 2.5 million mark sometime between mid 2012-13. And I'm quite sure the City of Vancouver is over 600,000 by now.
Wikipedia says 578,000 in 2006 compared to Seattle's 602,000 in 2009. Adding three years of growth onto 578,00 should put the City of Vancouver several thousand above 600,000.
According to this link
, as of 2006 the city of Vancouver accounted for 27% of Metro population and was absorbing 25% of its growth. Assuming the city still held 27% in 2009, it would be at 629,000 according to Statscan's latest released estimates (2,328,000). Those same estimates also state that Metro Vancouver added about 96,000 people from 2007-2009, meaning Vancouver should've absorbed 24,000 of that making for 602,000, but of course that doesn't include population growth from 2006-2007. Therefore the city of Vancouver should currently be larger than the city of Seattle, though just barely.