I was glad to see this today: Led Zeppelin cleared of plagiarism in Stairway case. Here's the article:

Led Zeppelin did not plagiarise the opening chords of the rock epic Stairway to Heaven from the US band Spirit, a Los Angeles jury has found.
It said the riff Led Zeppelin was accused of taking from Spirit's 1967 song Taurus "was not intrinsically similar" to Stairway's opening.
But it said Led Zeppelin singer Robert plant had access to Taurus. Stairway to Heaven was released in 1971.
The case was brought on behalf of Spirit's late guitarist, Randy Wolfe.
During the trial, defence lawyers argued that the chord progression in question was very common and had been in use for more than 300 years.
The prosecution had argued Led Zeppelin became familiar with Spirit's song after the two bands played on the same bill in Plant's hometown at a club in the English city of Birmingham in 1970.
Spirit's bassist Mark Andes testified last week he met Plant at the show and played snooker with him afterward.
Plant insisted he had no memory of that night, saying that in all the "hubbub and chaos" it would be hard to remember a one-off meeting 40 years ago.
Plant partially attributed his lack of memory to a bad car crash on his way home from the club. Both he and his wife suffered head injuries in the accident, he told the court, after the windshield of his Jaguar was left "buried" in his face.
The singer-songwriter also spoke at length about the creation of Stairway to Heaven.
He reiterated the assertions made by his bandmates Jimmy Page and John Paul Jones that the song had begun at the country estate Headley Grange and not the Welsh cottage Bron-Yr-Aur, contradicting decades of Led Zeppelin mythology.

Led Zeppelin, like Cream and the Rolling Stones and others, brought new life to old blues. I'm sure that ownership of many Led Zeppelin songs could be contested. Whatever the law says, I think they did what was musically correct: to build on what's good and maybe make it better - or at least make it their own.

-Joe-