This is a very intriguing post. It has a very nice initial question and quickly shifted into a discussion of possibility, science and understanding. Let me touch on both points briefly.
First, as far a breast implants becoming as “common” as ear rings, I feel that it should be rephrased as “popular” as ear rings. There has to be some persistent cultural pressures that motivates so many women to undergo augmentation each year. Keeping this number in check are the medical concerns, aspects of feminism, vestiges of prudishness, and the ability to afford or access the medical steps required. There will need to be a change in one, and more likely a few of these factors before this sort of change becomes common.
In other words, I feel that in western culture, there is more “popularity” for implants than is actually expressed in the number of women going through with modification.
Second, on the topic of absolutes, there is again the need to step back and look at how the concepts are being put forward. Concepts of “Laws”, “Truths”, and even “Understanding” are simply terms used to label items that have an element of the absolute to them. Yes, technically, nothing can be absolute in scope, knowledge, or application. Nothing (another absolute term) can be totally true or proven. It is always possible to weaken any absolute with examples that challenge or contradict it. However, this only works for items that can be tested or compared in some verifiable or repeatable way. Other concepts that lack the ability to be put through the scientific process should not be given the same emphasis or scientific import. Metaphysics, superstitions, and religions each lack components that would allow for the scientific verification or more accurately scientific testing. These concepts serve a different function in human society.
Third, to bring this back to the post at hand, there is every expectation that body modification will continue. Humans have modified themselves in all sorts of ways over recorded history and there is no indication that this proclivity will abate. How and what is modified will depend a lot on the social pressures, gender expectations, and each personal whim. Given the radical shifts in the idealized body images over time it is difficult to say with certainly that what is “hot” today will be vogue a few decades from now.
Last, Science is not a “belief”. You can not scientifically “prove” or “disprove” a belief. Nothing is “absolute”. Space and Time are relative and linked. The sun only rises in the “east” because that is what we call that direction from our current location. Oh, and to quote Monty Python, “My brain hurts!”