This is a slightly orthogonal impediment for SPDY. I have been searching for suitable articles or research conducted around this specific concern in vain.
Important prerequisite for SPDY is persistent-connection. All major sites which have very sizable wireless mobile client access switching to SPDY would mean that benefits of SPDY could potentially get lost. Here is the reason why - most of packet-based mobile networks are not capable of maintaining a resilient TCP connection mechanism across the black-spots and weak-signal areas of radio networks. If that is the case, what exactly is the point of SPDY adoption anyway ?
I have not seen yet any report on the measurable benefits of SPDY in wireless networks. Has anybody seen any ?