From what I understand, and I have not finished reading ALL the lore, the Gnomes were once flesh and blood creatures that got really into aracne energy. They loved it so much that they found a relic that threatened to consume them with arcane energy. Instead of backing off they were all, "LETS DO THIS!" and let the energy in.
So, now they are these etheral beings locked inside the confines of ther mechanical constructs.
In my mind this brings up one issue. If we do not have the option to have Flesh and Blood Gnomes along side these etherals (Which are cool), doesn't that leave a finite number of Gnomes?
Without the ability to procreate (Which I am not sure is something they have as etherals), how will the race continue? Wouldn't it be kind of fleeting to play a character that once dead there is no progeny of the Gnomes to continue the work and culuture you're playing an dieing race. Kind of a turn off for me.
Will there be Gnome children? Will there be a solution given later in the lore or in game as to how they keep going? Is there already something in the lore that I haven't read yet or missed?
I haven't read anything official, but you could cook up all sorts of fun ideas. They could be effectively immortal, but periodically elect to revivify as a new personality by fashioning a Maq'esh and then jump-starting it using their soul. They could have arcane foci that allow them to asexually reproduce by imprinting their standing wave on raw arcane energy and infusing it into a new Maq'esh. You can have those ones for free, Istuulamae but I could go on all night.
But seriously, I hear they reproduce like bears.