It Is What It Is

Maybe not. It all depends on what the meaning of 'is' is.

Seriously, though, this saying is seeing quite a lot of use lately.  It is a sort of present-tensed Que sera, sera.  Things are the way they are.  Don't kick against the pricks.  Acceptance and resignation are the appropriate attitudes.

From a philosophy-of-language point of view, what is interesting is the use of a tautological form of words to express a non-tautological proposition.  What the words mean is not what the speaker means in uttering the words.  Sentence meaning and speaker's meaning come apart.  The speaker does not literally mean that things are what they are -- for what the hell else could they be?  Not what they are?  What the speaker means is that (certain) things can't be changed and so must be accepted with resignation.  Your dead-end job for example.  'It is what it is.'

There are many examples of the use of tautological sentences to express non-tautological propositions.  'What will be, will be' is an example, as is 'Beer is beer.'  When Ayn Rand proclaimed that Existence exists! she did not mean to assert the tautological proposition that each existing thing exists; she was ineptly employing a tautological sentence to express a non-tautological and not uncontroversial thesis of metaphysical realism according to which what exists exists independently of any mind, finite or infinite.

'What will be will be' is tautologically true and thus necessarily true.  What the sentence is typically used to express, however, is the non-tautological, and arguably false, proposition that what will be, will necessarily be, that it cannot be otherwise.  So not only do sentence meaning and speaker's meaning come apart in this case; a modal fallacy is lurking in the background as well, the ancient fallacy of confusing the necessitas consequentiae with the necessitas consequentiis.

Now you know what I think about on those long training runs (3 hours, 18 minutes last Sunday).  Running is marvelous for 'jogging' one's thoughts.