Capcom has posted Event Quest information up on its official Monster Hunter Community website.
If you visit the official Monster Hunter Community website and click on the gem you should see new information on Event Quests and Arena Quests.
Capcom will be updating this page frequently so it pays for any Monster Hunter fan to visit the site if you want to know all the upcoming information regarding Arena and Event Quests in Monster Hunter Tri. You can visit the site here.