GT5 shipments are approaching the first GT ones: http://www.polyphony.co.jp/english/list.html
Once reached the 3rd place in the series, it would make sense to make the last effort to reach the 2nd, as it's not very far away, less than 900k, not impossible for a game that sold more than 2.4M last year and has already sold 690k this year.
1st place is the only target really unlikely to be reached, unless with heavy bundling.