If you were wandering around the comment section of the Spike age post from yesterday, Jim Miller braved the swarm below the break with a clarificaton on what he said on Twitter. According to him, Spike is around 7-10 years younger than Twilight Sparkle.
He also went a bit deeper with the mane 6, noting that at least within his canon, the mane 6 are of the same maturity level as someone between 16-22 years of age. This is slightly older than the original idea Lauren posted way back in the early days of 12-17.
Maybe it's time to editorialize this one? I bet we can trinagulate the actual ages based on birthdays and what ponies have said in the show.
Thanks to Micheal for he heads up.