Wizard101 to be fair, is quite an easy game as you can work with others in teams for bosses and dungeons.
I believe that a great update would be to create a badge system, where if you completely solo a boss or an entire dungeon, you get a badge. This will allow people who enjoy to solo to have proof of their achievements, and will also be more content in the game for people to enjoy. For example, if you soloed Tatrarus, you could get a badge called "Conqueror of the Underworld" for example. This would let people know that you soloed Tartarus.
While I wouldn't say Wizard is a easy game, (some of the strategies you have to do to win certain battles are complex and precise,) it does tend to be fairly easily with a good. IF you get a good group that works together, that is. Sometimes it's harder to win in a bad group then it is to win solo.
However, I really like this idea! Considering I solo a lot of things, one of the biggest reasons to solo is the sense of pride you get when you could do it all on your own. Having physical proof of this achievement in the form of a nice badge would definitely be welcomed! It might also encourage those badge hunters out there, that only do things in groups, to try soloing a bit.