What’s Different About Today’s Government Deficit and Debt?
As of today, the U.S. government’s current deficit and debt are indeed currently at unprecedented levels for peacetime—once we account for them appropriately.
"Mark to market" is one of those confusing terms that's been thrown around discussions of the finance meltdown. It's basically an accounting rule that means that a company has to put value certain assets on its balance sheet (in other words, to "mark") at what the market says their worth.
Steven Pearlstein at the Washington Post has a nice description of the term, why getting rid of it has become an obsession of the anti-regulation crowd, and a sensible proposal: