I grew up in Mesa and it's nice to see this happen here. Phoenix isn't a large tech hub and by Apple putting this plant in Mesa, this will help put it on the map (on a smaller scale)
Motorola, Honeywell, etc. Motorola was for long the largest employer in the state, perhaps still is. Arizona isn't heavy on RoR hipster startups, but for semiconductors, electronics, aerospace, and all the high-reliability serious software accompanying that, the Phoenix area can be considered a tech center. Same for Tucson.
I'm imagining that just because Apple puts a plant there won't change things much. Yeah, people will talk about it for a few days, but that's about it. I remember Google had an office in Arizona but then they closed it.
Well it's never going to be SV but when some other companies such as Ebay, Paypal, etc. went to Chandler and opened up offices, this helped other tech companies take notice and it's grown considerably over the past few years. I'm not implying it's going to attract other major tech companies to come to Mesa, but to get Apple to come is a big step in the right direction. If you would have said that a few years ago, people would have laughed. (including me)