Highly incomplete, just the stuff that caught my attention and stuck there:
January: Porpentine releases Nostrils of Flesh and Clay
January: Jon Ingold releases The Colder Light
February: some controversy at the XYZZY Awards; Cryptozookeeper wins five categories including Best Game
March: Flourish Klink releases Muggle Studies
March: the Apollo 18+20 ‘tribute album’ project, spearheaded by PR-IF, releases a whole bunch of games
April: Adam Cadre releases Endless, Nameless, his first game since 2005
April: Dave Morris and inkle release Frankenstein
May: The Rocket Man from the Sea wins Spring Thing
May: Victor Gijsbers (as Herman Schudspeer) releases the sixth Stiffy Makane game, Nemesis Macana
June: Varytale goes live, including Emily Short’s Bee
June: eleven games released in the Cover Stories event
July: two games released in the Andromeda Legacy minicomp
August: Nereida Scales’ ChoiceScript game Resonance wins Introcomp
August: Dannii takes over as editor of SPAG; next issue planned for December
September: The Emily Short / Liza Daly / inkle project First Draft of the Revolution is released, expanding the Lavori d’Aracne series.
September: Vorple for Inform 7 released
September: Victor Gijsbers begins opening up his roguelike/IF hybrid Kerkerkruip for collaborative development
October: StoryNexus launched
October: Emily Short launches Sparkly IF Reviews, intended to provide a space for saying honest-but-positive things about IF games and resources