That runs against time constraints. The forman is a flashback told in 3030 to his kids. The older seems to be at least 15, so for the show to run to 2013-14 (season 9), Ted would have to tell their mother "I love you" on the first date, and "Will you marry me?" on the second. Does that sound like Ted?
Or Season 8 could cover last 6 months of 2012. Season 9 could cover first 6 months of 2013. They did something similiar on that 70s show, they were forced to slow down the pace of the show.
But I doubt that season 9 will get made. Some of the actors are becoming really successful and they’ll prefer more time to appear in more movies.