Certainly, in many places you can be laid off with sufficient notice. However - at least where I've worked - the big difference is that I'm almost positive the company couldn't just go out and hire someone else for the job. They can get rid of the position alltoegether, but if they want to refill that job, they'd better have a very clear, legitimate, well-documented reason for terminating the person in that position.
My understanding is that under normal circumstances, a dancer whose contract was not being renewed would receive ample - like 6 months - notice beforehand; this was part of the union agreement. I don't think that was necessarily the case for those on so-called 'life' contracts, which is a sort of tenure that makes it much more difficult to dismiss a dancer (and something that I understand Hubbe hated, given his years at NYCB). The budget crisis permitted deviation from both of these restrictions.
What's going on now is perhaps more troubling. The dancers appear to have divided into at least two camps; the pro-Hubbe and the anti-Hubbe, and a fair number who are there to dance and just want the whole dispute to go away. Recently, some 30 dancers signed a letter of confidence http://bit.ly/GCtrhH
that appears to contradict a number of the complaints voiced by the union that is supposed to represent them. All of this no doubt makes for a very difficult work environment for all, no matter what 'camp' they're in.