The first of September is a big deal in the Harry Potter universe, as it marks the start of a new Hogwarts year. It's the day Harry, Ron and Hermione met. And today, it's the date that Harry Potter's eldest son James Sirius Potter arrives at Hogwarts. J.K. Rowling shared an update on James' sorting, and it should come as no surprise where he ended up...
In addition to announcing that James S. Potter was sorted into Gryffindor, J.K. Rowling also notes that Remus and Tonks Lupin's son Teddy is Head Boy, a Hufflepuff, and disappointed -- presumably because he hoped James would end up in Hufflepuff.
Rowling's update followed a previous Tweet, in which she was sure to point out that today -- September 1, 2015 -- is the day James S. Potter would be arriving at Hogwarts for his first year of school. This is, of course, going with the proper timeline of the books (not their publication dates or the movie release dates). Harry and Ginny would be in their thirties right now. That puts us a couple years ahead of the epilogue of Harry Potter and the Deathly Hallows, which sees James' little brother Albus embarking on his own first year at Hogwarts (and anxiously anticipating his sorting).
The fact that James is in Gryffindor is unsurprising, given that both his parents were in that house, not to mention his grandparents.
We don't know a whole lot about the Potter children, but that could change now that we're existing within the timeframe of their own time at Hogwarts. Perhaps Rowling will offer additional updates on what's becoming of them. There's also the chance that the yet-to-be-revealed plot of Harry Potter and the Cursed Child -- coming to the stage in 2016 -- will involve the Potter children somehow. We're already theorizing that James Potter could be the titular "Cursed Child" but for now, that's just a guess, based on a vague clue Rowling recently offered. Nothing has been confirmed, so we'll have to wait and see.
In the meantime, imagine James S. Potter, dressed in new robes, surrounded by his fellow Gryffindors, anxiously awaiting his classes, enjoying a feast in the great hall, meeting new friends, eager for the opportunity to break in his new wand and maybe see if he's a chip off the old block in the flying department. Congratulations, James Potter! (Insert lion roar here).