Steve on a coaching front and man management front I don't see things changing too much for you under Moyes, although I do question Moyes's tactics at times of not going for a win, but settling for a battle for a point. However that might be just his realism based on the limitations of his squad, but it could impact the late goals that have been so influential in many season for you (will there be Moyes time to replace Fergie time?)
But I think the areas he's untested will be the first areas where people will focus. How does he manage the likes of Rooney (or others who might want to leave), will he be ruthless when a player is not good enough (when do the likes of Giggs, Rio, Evra, etc no longer factor), and how well will he spend (he's done a great job shopping from the bottom shelf, but its a bit more tricky getting value from the top shelf?).
Personally I think he should be given at least 2 years, even if those are as you say seasons where you only win the Wenger cup (top 4 finish only). But I do wonder if the stability you've had, which I think is a major factor in your success, is something that comes from the club and therefore will continue, or whether it was from SAF just because he became unsackable.
I do hope its the former and not the latter, as I think that is how all clubs should be run (even if part of me wishes it was not how you were run!), and if it is the latter the day Man U starts chopping and changing I think will be soon followed by the end of Wenger (who along with SAF and Moyes are the only tenured managers), and the days of building a team for success will be replaced with the Stamford bridge/Etihad model of buy a team for success. That for me will be a sad day.