Black Canary has been Cast

From TVGuide, the role of Dinah Lance will be played by Alaina Huffman.

Like her comic-book counterpart, Smallville’s version is a martial-arts
expert whose superpower is a “canary cry” — a high-pitched scream that can
shatter objects and take down opponents. And, yes, she will sport the fishnet
stockings that are a trademark of the character’s costume.

So will romance eventually bloom between Green Arrow and Black Canary?
“It’s the very beginning of their relationship,” Gough says. “At the end of the
episode you clearly see that they have some sparks.”

Excellent news, now the only thing left is to see how she looks in blonde wig.