This column from Law360 examines the oral arguments from Microsoft’s appeal of the jury verdict in i4i v. Microsoft, heard by the US Court of Appeals for the Federal Circuit (CAFC) on 23 September 2009. In its questioning, the authors note, the CAFC took up several important issues on the appropriate standards for estimating damages that are likely to be relevant in other patent infringement cases, and attorneys preparing for trial in patent infringement cases should consider these issues carefully. The authors suggest that the CAFC may be reacting, in part, to concerns that damages in patent cases are unpredictable, that awards are not consistent with the value of the patented inventions, and that expert testimony is inadequately scrutinized by district courts before being presented to juries. The decision in the i4i case may address issues of suitable comparables, the use of unreliable techniques, and the need to bring more discipline and realism to damages testimony.