I have nothing special to add about the events in China 22 years ago, except simply to observe that they happened. It is worth continuing to note this anniversary in the rest of the world, since the authorities have all but effaced its memory within China. (Photo from May 1989; source here, via Kathleen McLaughlin.)
In my experience in talking with college students in China, it's not a question of having to be "careful" when referring to the events in Tiananmen Square on June 4, 1989, or using code like "May 35th." Even if you refer specifically to that time and place, most young Chinese that I've met have no idea what you are talking about. This is just an arbitrary date to them -- not one with resonance, like September 11, 2001, or November 22, 1963.
As Robert Sullivan has pointed out, the main Chinese news organs have room today to talk about the ongoing drought, and the epidemic of cheating on college-entrance exams, and the international good-will tour of Xi Jinping, the next-president anointee. But not for wallowing in an awkward part of the country's past. (English version of People's Daily front page today.)