Update: This feature was restored on or before 15 October 2012.
Gmail has a feature that "clips" long messages rather than displaying the whole message body. Googling around, I can find screenshots of the warning I used to see:
[Message clipped] View entire message
This message contained a link which would display the full message body.
This week, I've noticed long emails (over 100K) are being clipped, with no option to view the entire message body. I've verified this behavior in Google Apps and regular Gmail. The messages are definitely intact on the backend, and they can be viewed in their entirety in Thunderbird.
Does anyone know when and why this feature was removed? Is it coming back any time soon?