Jasper L. Cummings, Jr. (Alston & Bird, Atlanta) has published Fourth Circuit Rigidity, 110 Tax Notes 905 (Feb. 20, 2006), also available on the Tax Analysts web site as Doc 2006-2814, 2006 TNT 35-42.  Here is the Introduction:

The U.S. Supreme Court has reversed the Fourth Circuit’s ruling that, for purposes of determining diversity jurisdiction of the federal courts, a national bank is "located" in all states in which it has branches. Wachovia Bank v. Schmidt, No. 04- 1186 (U.S. Jan. 17, 2006). In your gut you know that the Fourth Circuit had to be wrong. What were they thinking? Why would the Supreme Court grant certiorari on such a narrow issue? And why do tax lawyers care? Are there state tax nexus implications here?