Take a page out of Smites book
So with the recent announcement of the removal or Dominion, and the uproar it has caused at the same time, I've decided to offer my two cents (Even though I'm English so it should be pennies).
Whilst I understand the gamemode may divert resources or cost a little extra money, it's sad to see the game modes being whittled down to literally just summoners rift. I've been playing the game for coming on 3 years now and it's certainly taking it's toll on my attention span within the game. Removing these gamemodes seems to be focusing the game too much onto one map, which unless they work hard with new champions etc, people are probably going to get bored very quickly.
In comes my idea.
So people all over the place have been suggesting featured gamemodes, and various other things like that. This is something that the MOBA Smite has been doing for a long time. Every day there is a new "Playlist" which includes one of the maps, some weird rules and maybe some specific champions. Those of you who are familiar with the game will know what I'm on about. One of the recent gamemodes was "Fire VS Ice", pitting ice based gods vs fire based gods in an arena map.
It's little things like this that keep you interested in the game. If you're not up for one of the normal gamemodes, you can always rely on there being some form of fun playlist available and it's this kind of thing that I'm suggesting.
I can't see it being difficult to do. Riot have already proven they have the resources available to make a gamemode available for a short amount of time, all you need is a random selection process and some creativity and you're good to go. It cannot be hard to implement some form of filter system in for only allowing some champions to be selected. Ideas for this may include a "Marksman Mode", "AP only", "Supportable Combat", even "Melee Only".
Riots excuse for these things normally is "People get bored of gamemodes after a week", in this case that will never apply since the rotation will be daily or weekly.
Realistically it'll be unwise for Riot to not attempt to replace Dominion with something. There's a huge risk of people getting bored much faster than originally.
Drop your own comments below, and if you've played Smite, what you think of their playlist system.
TL;DR - Riot should look at Smites daily gamemodes
~ Pouchey2