Which parts of the Apple ecosystem locks one in?
I have never purchased any video content (and never would. I'm okay with subscription services like Neflix and Hulu, but have no interest in purchasing video one off).
I have purchased very little music from iTunes. Maybe half a dozen albums? Hopefully they are DRM free, but not sure. 99% of my music is imported from CDs imported as MP3s and so portable to any other platform.
Other than that, what locks one in?
All e-mail, calendar, and contact data is exportable and portable to any other system.
The only thing that "locks" me into continuing to use Apple products is the continued convenience. I appreciate the ability to easily sync music and pictures between my phone and my computer and the quick sync of PIM data between phone/cloud/computer.
But I could easily port back to google services or use Exchange based services and I'm sure I could figure out syncing music and pictures with an Android device. But I like the way the Apple stuff works.
It's true, I've intentionally avoided iTunes content to remain portable, even though I don't have any intention of moving away from Apple. But I definitely don't like the idea of not having that option. But, I would argue, you only get locked in if you let yourself. It's not difficult to avoid and remain portable.
YMMV.
Cheers.