The dollar fell, then firmed, against most of the world's other major currencies Tuesday at mid-day, on word of yet another U.S. government intervention to ease the financial crisis. (For full currency data, click here.)

Still, the more important theme, many economists and analysts agree, is how well the dollar has fared given the remarkable increase in debt by the United States and the supply of dollars globally.

The dollar weakened about one cent to $1.3040 versus the euro and about half a cent to $1.5160 versus the British pound on Tuesday at mid-day, after the U.S. Federal Reserve announced it would buy up to $600 billion in mortgage and mortgage servicer-related debt and up to $200 billion in consumer and small business-backed loans, to free up credit in these sectors. The dollar also fell about one cent to 95.53 versus Japan's yen, and about half a cent to $1.1881 versus the Swiss franc.

Under the new programs announced Tuesday, the U.S. Treasury will provide about $20 billion in credit protection to the U.S. Federal Reserve, using money from the $700 billion Troubled Asset Recovery Program (TARP).

In September, the Fed's balance sheet totaled $924 billion, when the first wave of the financial crisis began to freeze credit markets and decimate stock markets around the world. However, if all loan guarantees are accessed, and if all of the remaining $780 billion debt is added to the Fed's balance sheet, that balance sheet would increase to about $3 trillion.

Can't say I'm a huge fan of Discover Financial Services (NYSE: DFS). Nothing against the company, of course, but when it comes to credit-card stocks, I'd much rather be aligned with either Visa (NYSE: V) or MasterCard (NYSE: MA). They make money on transactions at the register and don't have exposure to loans. With that bias fully disclosed, let me check out Discover's third quarter results, which the company discussed earlier in the week.

There really wasn't anything in the earnings release that made me want to buy the stock. Net revenues increased 8%, but earnings per share from continuing operations plummeted 27% to $0.37. Nevertheless, that was enough to beat analyst expectations by two pennies. The rough economy is hurting Discover. Charge-offs and reserves against them are negatively affecting the company.

Yet, there is an interesting litigation wrinkle to the Discover story as it relates to Visa and MasterCard. According to Bloomberg, some Wall Street experts believe that Discover may, at some point, settle its ongoing battle with the two card companies for $4 billion. It's a complicated situation, one centering on anti-competitive complaints. In the past, the major credit-card issuers wanted banks to deal with their cards only, effectively shutting out competitive forces. If a settlement isn't reached, then Visa and MasterCard may have to pony up billions more, since damages apparently could be tripled in this case if those two entities were to lose in court. That type of litigation news does represent a risk for those major card companies. Discover, no matter what, looks to be collecting a ton of dough at some point (it will have to share some of the windfall, Bloomberg says, with Morgan Stanley (NYSE: MS), which Discover was spun off from).