In the epilogue scene of Harry Potter and the Deathly Hallows: Part 2, these twin boys can be seen to the right of the Malfoys.
I think they may be Lorcan and Lysander Scamander, twin sons of Rolf and Luna Scamander. J.K. Rowling said that they are younger than the children of Luna's friends, which these boys are. These boys are also blond, like Luna.
Also, despite the film hinting at a Luna/ Neville romance, we know it doesn't work out. Matthew Lewis said that it was a "summer fling" before Neville marries Hannah and Luna marries Rolf.
Any thoughts?