This time , rather than speculations , I got my hands on some information. ( Been sometime since I posted in the forums as well :P )
Well , I'm not too certain whether it's a continuation or a side-story , but an Anime for Code Geass is definitely coming up so the rumoured R3 might not neccessarily by Shikkoku no Renya ( The Manga which features 3 Protaganists , Renya , a ninja-like main lead , C.C. , the immortal Code bearer and a guy who shares a slight resemblance with Lelouch )
The new Anime is titled as "Code Geass : Gaiden Bokoku no Akito" or under the English title "Code Geass :
The Ruined Land of Akito" . Generally , the story is focused on the year 2017 in the lands of Europe.
The official summary is as stated
"a.t.b 2017. A KnightMare unit of 11 youths embark on an operation to save their comrades stranded on the European
front, their odds of success only 5%."
By the way , here's a minor trailer of it : ( Don't expect anything epic :X )
http://animeblips.dailyradar.com/video/code-geass-gaiden-boukoku-no-akito-pv1-gaiden-pv1/
Information of it was released via an even disc called "Kiseki no Tanjobi" so it can be considered reliable
and official as well.
Anyways...ALL HAIL BRITTANIA! :P