Lumia 710:

The Tango/WP7.5 refresh firmware for Lumia 710 is now available on Naviform for many countries. Update might see a global roll-out soon.

Austria, Belgium, Denmark, Finland, Germany, Hungary, India, Indonesia, Malayasia, Netherlands, Singapore, Sweden, Thailand, Vietnam, China , Brazil, Chile.

 

Lumia 610:

Lumia 610 has been released in Asian countries only, as of now. The firmware for Lumia 610 is available on NaviFim for many more countries . United Kingdom, Switzerland, HongKong, France, Austria, Belgium, Denmark, Finland, Germany, Hungary, India, Indonesia, Malayasia, Netherlands, Singapore, Sweden, Thailand, Vietnam, China , Brazil, Chile, Greece, Italy, Malayasia, Poland, Russia and many more. So it seems very soon Lumia 610 will see a widespread global release soon.