the $1B charge does not hit the P&L >yet<. An accrual is a balance sheet item that is essentially a forced savings account for something that will hit the P&L in the future.
The charge is real and will eventually come from revenue in a P&L.
Post edit: not entirely accurate...it will come from revenue now, and impact P&L now...but the nature of the accounting entry at this point is internal..it comes from revenue and transfers to the balance sheet...(non cash meaning the cash isn't going out the door yet)...it will become a cash item when the expense is realized in 2013.