Since 12.10 is non-LTS and 13.04 is non-LTS and 13.04 will be end-of-life in a week, it might seem like 12.10 must have been end-of-life a long time ago. But that is not the case. 12.10 is supported through April 2014.
We have at least one closed 12.10 question where two close-voters voted to close with the EOL close reason. The question also appears to be an attempt to report a bug and I am not asking for it to be reopened.
However, this has alerted me to the need--equal to the need to remind people about how 13.04 is about to be EOL--to remind the community that 12.10 will not be EOL for another several months.
(That one question is not my only source of information about people thinking 12.10 is already unsupported. I've heard this misconception expressed many times within the Ubuntu community.)
Anyone who sees a question that is closed, but would not have been closed if its close-voters knew 12.10 remains supported, should vote to reopen it. (The example I gave is almost certainly not such a question, of course.) If it turns out we have many of these, it would be appropriate to compile a list in a CW answer here. But my hope is that we do not and that, by issuing this reminder, I've helped prevent there ever being many.
Why is 12.10 supported so long and 13.04 supported so short? This is because of a recent policy change decreasing the length of time non-LTS releases are supported. The change occurred after 12.10 was released and does not apply retroactively. This article has more information.
Ubuntu 14.04 LTS Trusty--which we do not yet support as it's in development--is to be released the same month that Ubuntu 12.10 Quantal goes EOL. So here's one way of remembering whether or not 12.10 is EOL: If a question about a problem in 12.10 is posted on the same day as a question about a problem in 14.04 LTS, and you'd vote to close the 14.04 question as being about Ubuntu+1, that most likely means the 14.04 question was posted too soon to (ever) be closed for being about 12.10.
More generally, the releases wiki page is always available to be consulted, whenever there's any question about whether or not a release is currently supported.