A lot of hay has been made over Windows Phone "Tango" aka CR3/build 8773 of Microsoft's mobile OS. The update contains a lot of minor things and is mostly focused on compatibility with 256MB devices for emerging markets and low-cost Windows Phones.
Nokia is hard at work with updating their ROMs for all Lumia phones and in fact if you use Navifirm to check, the Lumia 710 and 800 are getting heavily populated with new Tango updates, presumably being readied for roll-out in June.
