Per this article:  http://bit.ly/1gJA0yu at Tofino and Bob Radvanovsky:

• over 1,000,000 ICS/SCADA devices connected to the Internet discovered so far
• discovering approximately 5,000 new ICS/SCADA connected devices/day

Device types include, but not limited to:

• manufacturing/production control systems
• medical devices
• traffic management systems
• traffic light control/traffic cameras
• HVAC & building management systems
• security/access control to include video/audio surveillance
• data radios

and to keep it interesting, also found these connected to the Internet:

• off-road mining trucks
• crematoriums

In many cases, a web interface is enabled with default credentials in place.

I believe 1,000,000 is only a fraction of Internet-connected embedded/ICS/SCADA devices and that the rate of growth of new connections is way faster than anything that we saw in the PC days.