Patent injunctions are still discretionary, rules US Supreme Court

Essentially, the US Supreme Court has confirmed that injunctive relief for patent infringement is not in any sense an automatic remedy but remains at the discretion of the trial court, which is supposed to exercise its discretion after applying a four-factor equitable test:
(1) has the patent owner suffered an irreparable injury?

(2) are other remedies available at law, such as monetary damages, inadequate to compensate for that injury?

(3) considering the balance of hardships between the parties, is equitable relief justified?

(4) would a permanent injunction damage the public interest?

See also the coverage of this case in Patently-O ("a landmark unamimous decision"), Business Week ("a tepid triumph for eBay"), Jurist and The Raw Story ("a significant victory").