On September 17, the U.S. District Court for the Eastern District of Missouri entered an order clarifying that, even if a lawyer may be a witness at trial, this -- and Missouri Supreme Court Rule 4-3.7 -- ordinarily will not prevent the lawyer from handling pretrial matters.
The succinct case is Cross v. MHM Correctional Services, Inc., Case No. No. 4:11CV1544 FRB, 2012 WL 4092417 (E.D.Mo. Sept. 17, 2012).
I have previously written a column for Litigation magazine. That column is available here: http://bit.ly/Rz3bwO