I have always considered "as well as" a synonym for "and", but readily admit this may be a regionalism (or worse).
As well as does tend to be used that way these days; however, I believe that it "is supposed to" be a synonym for
in addition to and "is supposed to" presuppose that the item introduced by
as well as has already been spoken of as having the predicate. Thus, Nonverbis's specimen would work for me if "as well as" were fronted:
As well as being very informative, television is a tremendously entertaining medium.
That sentence would tend to be used only if television had already been spoken of as being very informative, or if it were taken for granted that one's listener(s) already believed that it was so. Putting a comma before the phrase in end position would help to bridge the two uses, but I still find the phrase awkward there.
A long time ago, probably long before I was born,
as well as was sometimes split into two parts, such that it could perhaps have been regarded as a correlative conjunction, at least in some uses. Thus, I believe that it used to be possible to write the variation I proposed in post #16 like this:
Television is known as well for being a tremendously entertaining medium as for being very informative.
