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.
Re: Badges for soloing certain dungeons and bosses.
Sounds good - but give badges for easy and medium difficulty battles too once in a while.
I soloed some very high health bosses because I was in the mood and didn't want to wait for backup. I wish I had something to show for it. Of course I did get a lot of drops.