How do you unlock more Summoner Icons?

The Summoner Icon popup says that you can unlock special icons via accomplishing achievements in the game.

As far as I can tell, I've never unlocked a new Summoner Icon, or at least have never received a notification that I have. Is there a known list of the achievements that you need to get in order to unlock new icons, like getting to level 30 (which I'm not yet), getting X amount of Kills/Assists/etc.? What icons can I unlock?

Solution 1:

The new summoner icons are to be unlocked via achievements. However, achievements haven't yet been released in LOL (You'll find the 'not yet accessible' tab in your summoner profile). There have been quite a bit of rumors lately on what the achievements would be, but I still haven't found anything serious on the subject.

Conclusion : Wait and See

Solution 2:

The only thing you can unlock for your current icon is a special icon-border (bronze, silver, gold). At least at the end of season 1 you had to reach a special elo in ranking games 3on3 or 5on5.

Solution 3:

New summoner icon available! Quoted from League of Legends website: "Show your Pulsefire pride with this exclusive Pulsefire Ezreal summoner icon and profile banner. Once you acquire Pulsefire Ezreal, you'll be able to select your Pulsefire-themed summoner icon. Selecting your new Pulsefire icon will also deck out your summoner profile with this sci-fi banner." Additional information found at: http://promo.leagueoflegends.com/pulsefire-ezreal/en.html