A German newspaper from Trier - you know, that place near the Lux border where Luxembourgers always go shopping - is speculating that the Grand Duke and the Grand Duchess will visit Berlin at the end of April. Apparently, the Chambre de Commerce has invited to a reception at the German Historical Museum on April 24th, in which the grand ducal couple will partcipate.
Upon request of the Volksfreund, the cour stated "there is no communication of an official state visit yet". So it seems not to be a full-blown state visit, only a meeting with business representatives in the German capital.
Another thing is for sure, together with Luxembourg's minister for the economy and foreign trade, Hereditary Grand Duke Guillaume will lead a Trade Mission to Canada between May 7th and 11th. The mission will start in Montreal for the first two days, continue to Toronto for the 9th and will be rounded up with another two days in Vancouver.
Source: Luxembourg for Business - Going International (Canada), Volksfreund