I was finally getting around to reading my 4E Essentials books, specifically the Heroes of the Fallen Lands Wizard, the Mage. After discovering the nice hybrid of Vancian and 4E Core magic, I noticed that a Mage, regardless of school, gains 3 Cantrips at 1st level.
What I'm getting at is this; Does a 4E Mage gain more Cantrips as they progess in level or do they only know the 3 Cantrips from levels 1 to 30?
They only know their cantrips they start the game with. However, it is reasonable to ask to learn an extra one as a feat, due to the precedent set with the Psion.
and with Gnome:
As the cantrips are Wizard Utility spells without a level, it's impossible to take them in your utility slots. (Though that would be a perfectly reasonable house-rule, considering the relative utility of cantrips and utility powers.)