What is queso (the sauce/dip)? Is it short for Chile con Queso? Queso is the Spanish word for cheese but (in the US) it is often used to refer to a cheese-based dip or sauce for tortilla chips. 

When I google "what is queso?", Google says "short for chile con queso". Looking it up on Wikipedia leads to a disambiguation page where the page for Chile con Queso looks like the relevant result. That page says chile con queso is "sometimes described simply as queso".

However I'm also finding a lot of people who think that it is just a cheese sauce that doesn't have anything to do with chile. 

So is queso short for chile con queso or are they distinct dishes?
Google is correct, in that it can be a shortening of 'chile con queso' (most typically in the US to non-spanish speakers).  But 'chile' is not the same as 'chili'.

'Chile' refers to peppers, so the dip is 'peppers with cheese'.

'Chili' is either an alternate spelling for the peppers, but more commonly in the US, it's a dish made from meat, tomatoes and chile peppers (chili con carne, literally 'peppers with meat')

And as Cindy pointed out, 'queso' may simply mean cheese and not a cheese dip.  (typically of a central or south american variety of cheese; in the US typically queso blanco, queso seca or queso fresca).  As best I can tell in the US, this is the more likely meaning when used by Spanish speakers.

update: and to make things even more confusing from an entomology standpoint: it's quite possible that 'chile con queso' led to 'queso dip' and shortly after lost its 'chile' ... and it's actually 'queso dip' that's been shortened to 'queso' by Americans.