Yes, I seen the topic, I was suggesting RFDuino as already available alternative. Thing is, Spark LE isn’t out yet and AFIK nobody knows when it will be. Architecture seems clear though, most likely it will consist of BLE Central shield for Spark Core and Peripheral type SparkLE. I suppose it takes about a year to have product out with decent library.
So, when SparkLE comes out, I will most likely try it. But since I am working on it right now, I will stick with what I know and what is available. And maybe get some HW design experience on the way (read “lots of burned silicon”) 