Larry recently addressed both these points. +, he thinks, would be a bad choice for concatination. I note even VB, which does use + as it's concat operator most of the time, has an & operator, for where it's unclear if you want to add, or simply concatinate two strings that happen to be numeric. Larry
As far as using abjunctation as the concat operator (IE the no-operator operator), that "can never happen in perl", since there are quite a number of things that have different meaning if perl is expecting a TERM or an OP, and will only be more in perl6. I can't seem to find Larry's post on this, but for example, << as here-doc (term) vs. shift-left (op).
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