Months of studying and looking forward to a date - i have no choice but to take it as im hoping to get admissions for 2012.
You should revisit this idea while your emotions from the grieving process progress because you do have a choice.
Life is filled with unexpected events and circumstances that interfere with how you planned and hope things will go. You have to make adjustments along the way since nothing will ever go perfectly according to plan.
If you are able to refocus and achieve practice test scores that are in your goal range during the last week leading up to the December test (On fresh PrepTests you have not been exposed to before and take under honest/strict test-day simulated conditions), go ahead and take it. If not, reconsider your plans and maybe withdraw your LSAT registration. You have until midnight the day before the test to do that so that nothing shows up on your CAS report and it does not count towards the three times in two years LSAT rule.
It is not the end of the world if you have to postpone applying to law school for one year. You should only take an officially administered LSAT when you are in proper condition to achieve the highest score you are capable of since the reported score has enormous influence on your admission chances to quality schools.
My condolences about your loss. Experiencing the death of a loved one sucks

and takes time to get over.