Well, it is now the 22nd and the group I wanted to join started a few weeks ago. As the start date approached, I realized that my enthusiasm had waned. I wasn't too keen on joining while I was still recovering, and felt that perhaps this might push me to do at a time when it wasn't smart to be pushed. I'm not running more than three times a week at the moment, and my mileage has yet to exceed 10K. My calf muscle has no issue while running, but I am feeling tenderness in my muscle on my rest days. I was warned about this - my scarred tissue is being stretched so it's not unexpected. I also notice it more when there is a significant change in the weather/temperature.
So - no group running/HM clinic - yet. Just solo, steady running to strengthen the calf muscle again. When I am ready to do so, I will add more runs to my week and then more mileage to my individual runs. Another half marathon clinic is offered in early June (the goal race is the Springbank HM that I listed as a 2012 goal). We'll see. :)