Ok, didn't read the opening post too closely. But then I'm wondering: Why teams in the first place? Why not just run a normal league where anybody can participate as long as a minimum number of games against different opponents is played?
This way encourages more experienced players to help each other and their less skilled teammates improve their game, more dialogue and brainstorming more often to optimize spellbooks and play beyond the forums. With a team there's more incentive to help strengthen the weaker players since you will be working together to get your team to win, even if you're not always playing team games. Hoping it will raise the population of competent and skilled MW players, I'm thinking it will encourage more participation from newer and less skilled players. We have a community of over 4000, but the majority are rarely active.
Also, having teams allows for the league to have a variety of legal formats, for both team games and non-team games. Otherwise we would have to make completely separate leagues for every format, since it's not fair to base an individual player rating on both team games and non team games, since having teammates that are more skilled or compatible with you would give you an advantage over equally skilled players that didn't happen to have such teammates when they play team games. However, a purely 2v2 league (using Lifebonded format; the optimal team rules that Zuberi came up with and Schwenkgott improved upon), would wither and die with the level of participation it has now, and that's the most popular variant. I'm hoping this league will make it so that variants like life-bonded 2v2 will have their own actual metagames.
Also, I'm betting that teams with cool names will create more enthusiasm and hype than individual players. It will make people feel more involved with the game and with the community.
I'm still hoping that the old league's challenge board gets updated again though, since it would still be good for players to see their individual win/loss ratio in each format and compare to other players so they can have a useful way to measure their progress (as well as the occasional bragging rights).