According to reports Nokia was firstly researching for Android over Lumia handsets that too before the Microsoft deal this month. That really makes us think about a better future of Lumia even without the Microsoft deal with Nokia.
Nokia had the option to get out of the Microsoft partnership in late 2014. Testing out Android devices was preparing the company for such a future. According to NYT's sources, getting Nokia devices to boot Android was an easy task to accomplish from an engineering perspective.
Nokia tested Android on Lumia devices before selling to Microsoft
The device has only 3% of the market in 2013 for now and android has 3 Quarters of devices running. So it will be a real possibility that Nokia would have come up with android but after the Microsoft deal we can thing of this dream being forever a dream. As Microsoft will never plan this.