Flames Central has become the primary mid sized concert venue in Calgary. It is booked really frequently. It is the Palace Theatre after all, a great concert venue in a great location. Here's the link to there list of upcoming concerts, which includes among others Metric (perfect kind of place to see a band like that). Seems to be taking over concerts that might have gone to Mac Hall.
http://www.flamescentral.com/concerts.php
And yes, the Republik is back. I remember it hosted a bunch of Juno week concerts. I suppose Broken City kind of replaces the Night Gallery for that size of venue. I miss the Night Gallery for night life.