Reuters India, and the Kyodo News Agency both report that the Chinese Foreign Ministry called in the North Korean Ambassador, to express concern over North Korea's apparent intention to flight-test its TD-2 missile.
Either way, this is serious cause for saying "Uh oh." Formally calling the ambassador to the Foreign Ministry for an official government-to-government communication probably means (1) that China was unable, through quiet, back-channel unofficial talks, to get satisfactory assurances from North Korea that the missile test would not proceed, and the Politburo has decided to up the ante; or, (2) China has concluded the test will go ahead anyway, and China wants its protest noted for the record.
Either way, North Korea appears to be intent on proceeding. Given that China is North Korea's economic windpipe, lifeline or whatever metaphor you want to use, the only question left before the house is whether China is serious: i.e., whether the North Korean test will result in economic pressure from Bejing.
Given North Korea's proximity to China, and the fact that a North Korean economic collapse or temper-tantrum would cause serious humanitarian and economic problems all along the Yalu and in Manchuria, I tend to doubt that China will use its leverage, and insted will, as everyone else implicated in the Problem of North Korea has done -- opt to punt the issue down the road again. Consequently, possibility no. 2 above is probably more likely.