I've just resumed commuting too, I have one week of 12km each way under my belt, hope to go to a 25km each way commute next week. (I ride to a yard, pick up a vehicle to drive the rest of the way to work - 48km total + I'm on call every third week, when I have to drive to work)
I'm leaning toward the old road bike commute vehicle. I picked up an 87 Bianchi Strada (nothing fancy) for $35 at a yard sale and it is just so much more fun to ride than the mountain bike I had planned to use for a commuter. I still have to add fenders, rack, etc., but I'm pretty sure I'll be putting this stuff on the Bianchi instead of the Norco. I'll probably end up using a combination of both! (I'm going to the police auction next week to see what's there, too. - One should always be trying to upgrade the fleet!)