-Gamefreak has stated that they do not have a particular pattern of release for their games, but I have noticed that 3 "main games" (i.e. R/B/Y, G/S/C, D/P/Pt etc.) and 2 remakes(i.e. FR/LG, HG/SS) are released each generation so all together its a total of 5 games Gamefreak develops each generation (after Gen. 2 obviously). Obviously only 2 "main games" have been released in Gen. 5 so we can expect at least another game before Gen. 6 starts. I have also noticed that each generation has a 3-4 life span, Generation 5 debuted in 2010 (2011 in NA/EU) so we can at least expect either Gray, B/W3, R/S remake or a completely new project by Summer 2014. I do not think Gamefreak will break the 5 game cycle. If there is a R/S remake, it will most likely be release around Q3 of 2013 considering the fact that they not spoken about it and they will want to reach the holiday shoppers. What's better than a R/S remake and a 3DS XL bundle for Christmas? Huge profit for Nintendo!
But who knows, we have no idea how long they have been developing the game and Spring/Summer releases are common.
while what you say is true, you have to look at the other 2 games(remakes) they have released in the pass. As others have stated here many times , they had to be remade because there old cartridges were not able to communicate with the 3rd and 4th gen.Thats no longer the case now.
And if GF released the remakes they would break the 5 game rule you brought up. To be really honest i think they should hold off on gen 3 remakes until gen 7