Generally speaking, it comes from this;
http://classic.battle.net/war3/neutr...intinker.shtml
The Tinker hero from WC3. WC3 is e base for all WoW classes. Especially the expansion classes. The reason so many believe that Tinkers are the next class is because the Tinker is the final hero unit from WC3 that doesn't have a class equivalent, or has its abilities farmed out to other classes.
On the other hand, since Technology is a large archetype, Blizzard could implement the class in a variety of ways, along with hints of the Tinker hero unit from WC3. We've seen a variety of technology class applications in WoW. Everything from the Tinkers in the Brawlers guild, to Geblin Mekkatorque, to Siegecrafter Blackfuse.