It was done quietly Thursday, but the news is just getting out today. Bloomberg News says Samsung has dropped the U.S. lawsuit claiming Apple had copied many Samsung innovations in the interest of "streamlining" the legal hornet's nest between the two companies.
The Samsung lawsuit was brought in April as a response to an Apple lawsuit, still pending, that claims Samsung's mobile phones and tablets have copied Apple designs. It appears Samsung is doing this to consolidate its legal pleadings, as the US suit was done to quickly establish Samsung's alleged case against Apple. You can read some detailed analysis of this case from the Foss Patents blog.
The legal paperwork continue to mount. Last Tuesday, Samsung asked the International Trade Commission to block several Apple devices for sale due to patent infringements.