This board is under IL, so Ill use IL law.
If you state is MA, then it may be different, and it may be different if you have an employment contract rather than an at will relationship.
In IL, and employer can only legally change a payplan if the employee is first notified. They can not retroactive a pay plan. Check your states department of labor website and statued.
Sounds to me like moreover the company is straped for cash in these very tough economic times, the severe global recession, and credit crises. (Ever watch bloomberg overnight ?)
Sounds to me like there pulling one over on you for 1 quarter, a trick to get the work from you for 1 quarter without objection.
Now the other serious consideration is are the options worth anything ? What is the strike price? What is the companies stock worth ? How liquid is it (Can you sell the options or stock tommorrow and how much are they worth in cash?) If the answer is not really much, then you may want to consider finding another job ?
If you do decided to find another job, good luck the job market is vary tight, but if you a skilled professional, and you can take your skills to the competition, you might just strike some gold.
If you do leave, or mention you might might leave, you might try to pressure the company to pay the bonus in cash as previously promised. If they had had you sign you pay plan in a pattern for quarter past, and didn't have you sign one last quarter, that shows inconsistancy and tell them so, you did not agree to work for worthless options, so there fore you bonus structure stands as the last one you signed. (Just be aware that once start disputes about your pay, you may be targeted for termination, this may give you a wrongful termination claim if you file with your state department of labor for wage claim.) Just be aware the State Department of Labor has limited resources and doesn't do that much for you, but the bluff can work, or if you want, at least get you wrongfully terminated so you can collect unemployment. (Job market is tight though, tens of thousdsands of blue chip company jobs being shed every week.)
Try to deal with your company managers, reasonably and respectfully first, to resolve or negotiate a settlment to the dispute. In that Also, consider if its worth staying at the job. You may want to get that resume flying out there, to at least see what you might be worth somewhere else. If negotiation with the company fails, and you decide its not worth it, then you can hit them with a wage claim, get wrongfully terminated, then sue their asses, while you collect unemployement.
Consult an attorney for that.