Now that Apple's (AAPL) fantastic quarterly earnings are behind us, the question for investors now is what comes next for the technology giant? Investors are no doubt looking forward to the 2015 product releases, which definitely include the forthcoming Apple Watch. Aside from this, rumors suggest Apple is working on a self-driving car, as well as a possible television. But with the iPhone 6 likely to be Apple’s major growth catalyst this year, is there cause for concern from increasing competition? Cheaper devices at lower price points may threaten Apple’s fantastic margins and growth.