A leaked O2, Germany document springs two new Nokia device names. While Eros can be actually “Eos” and this may be a typo, the second device is yet unknown and is codenamed Mars. We can simply guess, as we have one more device RM-941 passing through FCC along with EOS (RM-877 and RM-875). So, as according to the source article, these devices may be on sale in July-August so our best guess is that RM-941 may be codenamed Mars and may see an announcement either along with EOS or separately in July.
Even Digitimes has confirmed from “Compal” which is supposed to manufacture Lumia devices that Nokia will announce a low-end and mid-range device as well after Lumia 1020.