I'm glad the thread has finally started being about Tinkers again, for what it's worth. But arguing that the class's mechanics would be too similar to an existing class is just plain silly. The only way Tinkers, or any new class, would have mechanics identical to an existing class is if all of the creative people in the class design department just dropped dead all at once, and the only way a person can argue that point and believe it is if he was born unencumbered by the slightest shred of an imagination.
Now, they could indeed "reskin" a shaman and make him summon robots instead of elementals and fire his spells out of a gun. But stopping there is just being lazy. They could, in fact, "reskin" every class into some variety of Tinker. Even monks. And if and when they come up with a new class which is not a tech class, you can bet your ass it will be possible to make it into a tech class purely by changing its aesthetics. Doesn't matter what it is, or could be.