In other words, a final decision by the US PTO's TTAB can now collaterally estop a court from later re-adjudciating issues that have been already decided. The particular issue being precluded in this case was the likelihood of confusion standard as applied between two marks.
In the decision, the Supreme Court recognized that issue preclusion is not only limited to situations where the same issue is before two courts, but also applies where a single issue is before a court and an administrative agency. The Court noted that the right to a jury trial does not negate issue preclusion, even if the judgment in question was entered by a juryless tribunal. Moreover, there is an absence of Congressional intent that would otherwise indicate issue preclusion as being inapplicable to TTAB decisions. Therefore, where a TTAB decision has not been challenged (i.e. appealed), it will be found to have a preclusive effect as to any materially same issues.
The ruling in this case will not only be limited to TTAB decisions, and will likely also affect future Patent Trial Appeal Board (PTAB) decisions in IPR and PGR proceedings, and any parallel district court litigation, for the same rationales given by the Court in this TTAB case. Going forward, individual decisions of fact or law finally adjudicated in future TTAB as well as PTAB proceedings will likely carry the same preclusive effects as if made by another court.