The Ending [spoiler]
I'm just going to retype this since I just saw the DVD with director commentary.
The director notes originally he was going to just let him stay in the "what if" universe but instead changed it so that it was provide a possible future, which makes perfect sense. So, when the "what if" vision of sorts ends, he meets up with his old gf again & they start over again.
The director notes that they are about 22 at the start and in their mid-30s as the "what if" begins. Women do have children in their mid-40s, so the ending taking place "eight years later" as she has her younger DAUGHTER is okay enough. The 1989 college jersey (film released in 2010) fits into this time line.
Thanks for the two replies.