According the Department of Justice (yeah, that's what they actually call themselves missing the Orwellian irony,) he's been charged, but the press release makes no mention of an arrest. I don't know if Vietnam has an extradition policy with the US or Germany, so it may be difficult for them to impose their injustice upon him. Let's hope.
Coinciding with the ChipMixer takedown efforts, Minh Quốc Nguyễn, 49, of Hanoi, Vietnam, was charged today in Philadelphia with money laundering, operating an unlicensed money transmitting business and identity theft, connected to the operation of ChipMixer.