Smartphone and tablets seem to be fighting for the same market, but the truth is, what smartphones are taking over is the market for the telephony service, the camera, newspapers and casual meet-up sessions (think Facebook apps), while what the tablet is taking over is the market for laptops, books, notepads, sketchpads, whiteboards, TVs, work files, game consoles and many many sessions of business meetings.
In other words, there has never been any competition between the two, and there never will be.
The Phablet on the other hand aims for all these market segments, making it the real rival for both the Smartphone and Tablets. Gotcha, Phablet!