Virtues are a category of trait. You can have any five virtues active at once (at higher levels). Each virtue has up to ten ranks, providing three bonuses that scale based on how many ranks you have in that virtue. You gain ranks by completing deeds, such as exploring the farms of the The Shire, finding the lost lore of the Cardolan princes, or slaying wargs in Angmar or the Lone Lands.
Only one deed currently goes all the way to ten, and only since Book 14 went live. More may hit it when the new zone opens up. It is unclear whether they will still stop at 10 with the expansion pack or whether they will scale higher with the higher level cap; otherwise, they become worth relatively less, as 30 Agility is more meaningful at 50 than 60; or not, if the stat cap stays at 500.
If the cap does not rise, we will very soon have more ranks available than necessary. There will be options. This is a neat notion to me. Currently, you have quite a bit ahead of you if you want to cap anything. There is a more or less continuous group going in Sarnur for people farming trolls. You will likely hit the experience cap long long before you run out of quests, and there are always several ways to go about seeking experience. It might be nice to provide similar trait options.
I cannot see anyone killing 360 worms in Ram Duath if there are other options. It might be meaningful to developers to see which deeds fall in the category of “only if I need it, only if there is no other way.” That data is probably spoiled by incorrigible completists like me. Like me and half the other gamers in the world.