Yes I understand it to mean IQ as well - often it is used as meaning anyone with an IQ over 70 and therefore not judged as having an additional learning disability (70 often being the cut off for LD schools etc)
However i think it also often gets used as meaning good speech / level of functioning too
IQ can be very misleading in Autism as my DS can score within the average range on many academic or skill tests but his actual everyday level of functioning in terms of speech and practical ability to do things for himself is at least 2 years delayed (he's 4). On the triad he scores as severe even though his IQ is apparently normal.
Also I expect his level of functioning to improve as he gets older and for him to move up the spectrum
This can even relate to Aspergers as you can have young adults at university with very high academic IQ and advanced speech ability but they can be unable to organise themselves, take a shower etc etc
So in my mind academic IQ is a bit pointless if it does not translate into independent practical use of ones IQ. There should be an academic IQ and a functional IQ.
Also we now know from adults with autism who have written books that being non verbal does not mean low IQ - in the past I think it was assumed if you could not speak you were low functioning but then some non verbal adults started writing novels and blogs so that myth was blown apart.
Children with autism often underscore on formal IQ tests for their cognitive ability because so many of the tests are language based. So its known to be very unreliable to assess a child's IQ
Temple Grandin for eg would have scored as severe ASD and LFA as a 4 year old child (no speech) but is now the most famous HFA person. So her level of functioning has changed dramatically over the years. She is often referred to as Aspergers but in fact she had classic autism (with severe speech delay).
Under the new diagnostic criteria DSM V being proposed I think a child may get assessed against the triad so could be severe in one area and mild in another - and they also plan to include sensory problems. I would think (hope) in future you might get a more detailed diagnosis.
If I was allowed to give my DS his dx I would score it as:
Classic autism, with speech delay but no additional learning disability (IQ in average range)
Language deficit - severe
Social deficit - severe
Repetitive behaviours - severe
Sensory issues - mild
Challenging behaviour - mild
And that could change over time eg as he develops language
Its also often missed that classic autism children are delayed and grow up much slower than other children but that does not necessarily mean they will not get there in the end. So many children will start as severe and end up moderate or mild.
At the moment my DS has a moderate autism dx but in my view this is not accurate - he is severe - so in effect his IQ score is cancelling out his autism severity score and meeting in the middle. It would be much better in my view to score each element individually as that would actually reflect the reality.
If you look up the proposed DSM V that can be useful to score your own child.