I don't agree that graphic design, illustration, multimedia producer, etc. are inherent roles of an instructional designer, regardless of your comment to Maurizio above about one person makes a team. The instructional designer's role, in terms of illustration/animation/etc, SHOULD be to frame out and define the graphics for the associated content. I'm not saying there aren't qualified IDs, but by and large, they do not have the prowess to pull it off. A professional illustrator, especially one who's area of expertise is eLearning, should be the one to bring the ID's ideas to life.
As far as look and feel of the course, that is better left to people who live and breathe design. A pet peeve of mine is seeing these SL characters used and abused because they look pretty. It's just fluff on a page that has no benefit to the learner.
I think we're living in a age of, "it's good enough," and that's sad. A lot of this has to do with companies stock piling cash while citing the poor economy. Do more with less is the mantra.
That's my nickel's worth.