Bad for us but can you blame him?
Last year ended with threats of strike action and general agreement in the teaching profession that there simply isn't enough money to fund the Assembly government's far-reaching curriculum changes being thrust on schools this year.
This rocky start has been exacerbated by the announcement that the Australian, who in January 2006 was parachuted in to phase in tri-level reform to the Welsh education, is about to leave us in the lurch.
Speculation is rife over why Mr Marshall is leaving. However, who can blame the head of DCELLS, as it is now known, for wanting to move to pastures new? In a poll out last week, Canada came second only to New Zealand as the country to which most Britons want to emigrate.
For Mr Marshall, the chance to work in Ontario provincial government, where educational standards and achievement are high, must be a dream come true. In Wales, he might have begun to see an impossible mountain to climb.
Far from the collaboration he was seeking, the year starts off with dissension and discontent from local authorities, teaching unions and school heads alike. Strike threats hardly bode well for the most important year for curriculum change in a decade.
And all this on the back of "dire" rankings in the recent reading, writing and science results of Wales's 15-year-olds released by the Organisation for Economic Co-operation and Development - a result Mr Marshall always claimed would be a true test of where Wales stood internationally.
Mr Marshall came to Wales in a bubble of positivity and made it clear he was not going to take any prisoners in achieving his objectives. He might not have reckoned on the political roller coaster of the past 12 months or the negativity he encountered.
Rhys Williams, of the NUT Cymru, wonders whether the lack of funding might have been a deciding factor in his swift departure. But Mr Marshall has always pointed to evidence that showed the amount of money spent per pupil did not always spell success. Maybe his decision really was based, as Professor David Egan says, on "a job too good to turn down".