Congratulations on winning your long fight!
Back pay is tied to the application date. They will go back up to one year prior to the application date. You always want your onset date to be several months before the application date so the 5 months withholding doesn't affect you.
No taxes were taken out of my backpay. I"ve been reading IRS Publication 915. Can't find the one for 2008 yet, but the 2007 version has worksheets in back to help figure out how much of the backpay is taxable. Even though I received a large lump sum and don't have the right forms in hand yet, it appears that there will be very little tax due. The form is at www.irs.gov/pub/irs-pdf/p915.pdf
They allow you to calculate taxes as if you received it in the prior years, if it helps lower your taxes. It also depends on your living situation, and if you had other taxable income. I think the lawyer fees can be counted as an expense.