Most of what was found is new interactions between the heroes (especially for Sombra, but some others as well), but there are a few stand out references to other things.
Via Venxa on Reddit: https://www.reddit.com/r/Overwatch/comments/5eeamk/some_heroes_interactions_sfx_xmas_overwatch_ツ/
Christmas Theme (presumably for the holiday event, which will assuredly not be called Christmas in the actual game): https://clyp.it/idbkejls
Announcer (Athena) lines:
"Now entering the arena": https://clyp.it/ggo4pisy
"Challenger": https://clyp.it/vsyqbp1y
"Gladiator": https://clyp.it/g5kbh5dg
The person who dug up the sound files also speculated this is the loading music for the Arena mode: https://clyp.it/gsgev3oo
Via Venxa on Reddit: https://www.reddit.com/r/Overwatch/comments/5eeamk/some_heroes_interactions_sfx_xmas_overwatch_ツ/
Christmas Theme (presumably for the holiday event, which will assuredly not be called Christmas in the actual game): https://clyp.it/idbkejls
Announcer (Athena) lines:
"Now entering the arena": https://clyp.it/ggo4pisy
"Challenger": https://clyp.it/vsyqbp1y
"Gladiator": https://clyp.it/g5kbh5dg
The person who dug up the sound files also speculated this is the loading music for the Arena mode: https://clyp.it/gsgev3oo