They declined to pay for the last nine episodes of this season which means good as cancelled though not stated as such. There seems to be some possibility it might move to SYFY which is in part owned by NBC and a good idea in my opinion. I was just starting to warm up to the show when production halted. This is one of the reasons I usually don't watch new series.
They had a real problem though, as when the Spectre ever decided to be really shown, that would pretty much end the series, as he would make sure to judge all of the baddies...
And think NBC billed the last show as end of season one, not end of the series!