If you've been a network engineer in the past few years, you'd know exactly why you'd need to break SSL. Traffic prioritization used to just require looking at the TCP/UDP port- SMTP and FTP could be low priority, while HTTP was medium priority, and RTP was high priority. Then users started using non-standard ports, so you needed to look deeper- you start looking at the content-type header in HTTP. By doing this, you could still make the octet-stream and application-pdf low priority (file transfer) while the text/html would be higher priority and audio content-types the highest.
This was all well and good, but then the web moved to SSL. Not just for email or banking, but even sites like Youtube and Facebook. Now, QoS devices (which are critical in bandwidth limited situations like zooming across the sky near Mach 1 at 30k feet) need to peer deeper into the packets. In an enterprise environment, this is done the same way Gogo is doing it, except we control the list of trusted CA's on the computers, so we can tell our users to trust the (fake) certs that we are signing.
It's not a great solution- it's essentially a man-in-the-middle exploit. The better alternative would be for sites like Youtube to honestly set the DSCP header, but that's not going to happen...