A post referencing rocketslay's post of Tyler1 playing TF2 (http://www.teamfortress.tv/39512/loltyler1-playing-tf2), TF2 needs a lot of things, but the best way to make us a relevant esport is if we start growing again.
Tyler1's stream highlights how confusing this game is to the players who have just started up the game.
First off, the moment you launch the game it should first walk you through personal game settings, such as your sound settings, mouse accel enable/disable, sensitivity and keybindings. As well as some sort of interactive way to test what sensitivity you are running at, rather than having to tab in and out of settings/console every time you want to adjust it.
Secondly, (and this has been discussed before) the devs need to remove the tutorial showcasing only soldier, engineer, demoman and spy. There should be a compulsory tutorial after you run though your settings, teaching the player the basics of each class mechanics (scout double jump, medic healing, sniper and spy headshots and backstabs, etc.,.). After which the game would recommend, but allow the player to skip, a second tutorial perhaps showing some more complicated game mechanics such as rocket jumping, crit heals and perhaps the speed at which medics charge their uber and how it's different depending on the healing target's current health.
Another thing this game really needs, is having damage numbers automatically enabled, as well as hit sounds - again, enabled automatically but they could still to toggle on/off through your personal settings "orientation".
Lastly, and this might be a controversial change for the more nostalgic players.. is a redesign for the default HUD. Our current hud is a little clunky and certainly outdated for the new huds that are being released in other games.
Just a list of a few things that would take a bit of time to release, but I feel would greatly help the new player base and reduce the number of new players like Tyler who play for a few minutes, but are demoralized by their confusion from the great, yet complicated game.
edit: Papa Bless the staff member who fixed my title.