eLearning, E-learning, E-Learning or e-Learning?

I agree with what others are saying about consistency being the most important thing. But for me, it boils down to the usage for other similar terms.  When is the last time you saw "e-mail" or "eMail?"  The simple spelling and case for "email" is now widely accepted.  The similar spelling and case for "ebook" and other similar terms have now also become common. 

I feel like it's time for elearning to follow suit, but this is just my personal preference.  I have a hard time using the spelling and case "e-learning" or "eLearning" if I'm not also going to use "e-mail" or "eMail."