I agree that it looks odd. However, especially in applications like cryptography, I think that removing the ambiguity of "megabyte" (i.e. do we mean 10^6 or 2^20 bytes?) is worth the introduction of a new term.
Do you mean an additional new term to mean millionbyte? Because the existence of mebibyte only makes 'mega' even more ambiguous. You used to be able to know from context.
I was referring to the "mebi" prefix. I agree that, currently, the old SI prefixes have perhaps been made slightly more ambiguous due to the introduction of the new prefixes. It is my hope that the computing community will eventually reach the consensus that the SI prefixes refer only to powers of 10.