I don't take any awards seriously in that I don't take anybody's word that something is the "best" in any given category. However, I do take awards seriously as a marketing tool.
In the animated feature category, I'm happy to see that The Illusionist received a nomination. Of the three nominees (the other two being Toy Story 3 and How to Train Your Dragon), it is the film most likely to benefit from the nomination in that it is the only one of the three that is still in theatrical release. This should give it a bump at the box office. It will also boost the eventual DVD sales.
The other two films have already made most of their money. Their theatrical runs are over and their DVD sales peaked before last Christmas. While the nominations may goose their DVD sales a bit, the overall impact on their profits will be minimal.
The nomination of The Illusionist is also good for drawn animation. Anyone trying to finance a drawn feature will use this nomination as proof that the medium is still artistically viable. No nominations are needed to argue that for computer animation at this point in time.
Having said all of the above, I would be very surprised if The Illusionist wins. I think it's a given that Toy Story 3 will win the category. Its nomination for Best Picture is an indication of how much Academy members like it, but they will never vote for it in that category. The Illusionist has a better chance of winning Best Animated Feature than Toy Story 3 has of winning Best Picture, and I wouldn't place a bet on either occurring.