Update May 12th: The show has been officially canceled.
The CW has just announced that The Secret Circle will conclude it's Freshman run on Thursday, May 10th following The Vampire Diaries. A season 2 renewal has not been made official, but TSC remains the second highest rated series on the CW. The companion series debuted strong following TVD, carrying over all of it's 3.05 million viewers. However, The Secret Circle has had a slight decline in viewership, going on hiatus with an average of 2.06 million viewers. According to an insider at the CW, TSC is currently 'on the bubble'; meaning the series' renewal depends on ratings and how many new pilots the network picks up.
All that said, I believe the show is a lock for Season 2. The witchy drama carries strong ties to The Vampire Diaries and is looking good for a possible move to open the coveted after-TVD spot to one of the CW's new pilots. The Secret Circle's ratings continue to be competitive for the network, above other 'bubble' shows like Nikita, Supernatural and CW newcomers, Hart of Dixie and Ringer. In addition, Ringer's finale has been set for April, making a renewal for TSC look even better. So, sit tight fellow fans, keep watching and I will keep you up to date on the fate of The Secret Circle.