This is something that gets discussed every year because they put that in the rules but then I always see people with those things anyway. I've brought large suitcases and small dollies before myself without issue. I think those things within reasonable size should be okay, because otherwise I'm not sure how they want us to transport our things if we bring more than a single tub of items.
EDIT: I just received an email with some info about this, apparently dollies and carts are allowed up to the doors of the South Hall but are not allowed inside. So you can use them from your car and in line but will have to manually carry things once you get checked in basically. This is frustrating for the people who end up being located in the back of the hall since it's such a far walk to carry all your things. It does also say only "Rolling dollies, carts, wagons, and other similar items are not allowed inside" but does not specifically mention regular suitcases, so that might be a good method if available to you as far as moving things inside.
EDIT: I just received an email with some info about this, apparently dollies and carts are allowed up to the doors of the South Hall but are not allowed inside. So you can use them from your car and in line but will have to manually carry things once you get checked in basically. This is frustrating for the people who end up being located in the back of the hall since it's such a far walk to carry all your things. It does also say only "Rolling dollies, carts, wagons, and other similar items are not allowed inside" but does not specifically mention regular suitcases, so that might be a good method if available to you as far as moving things inside.