I've had my key "stuck" in the ignition several times - but I always seem to be able to get it out eventually. I usually try pushing it back in (all the way to "start" mode) and then trying to take it out again. I've tried everything from taking it out of Park, pressing brake petal, ... anything else I can think of - eventually it will allow the key to come out - usually in less than a minute. I've owned my 2007 passat for about 3 months now and it has happened 3 times. The last time it happened, I put a new unprogrammed key in the ignition (was testing some sotware) and the immo system activated - but I was still able to get the key out (but was really panicing...).
Bottom line is I don't know what actually releases the key - just keep trying and it seems to release....
Bottom line is I don't know what actually releases the key - just keep trying and it seems to release....