I know there's a low chance of my theory coming true, but I really do think that the developers of SF3 intended Q to be David, the black agent in his ending. *points to theory in sig* I don't know if they'll ever pick up on his identity clues or whatever, but I really do feel that David was intended to be Q himself, or possible one of many Mysterious Men across the globe. Either way, I just want Q back, poor guy only got one shot at fame and awesome.
Also, random factoid, but David and Juliana are supposed to be a nod to David Duchovny and Gillian Anderson from X-Files! Hah!
For instance, after 3rd strike, chun li retired and started taking care of childrens, if this game is after 3rd strike, she would be fairly old (40 ~50 years old if the story happens between 2000 ~2015), and why she came back into action?
Good questions, here's the interesting thing though. Capcom seems to have been slowly altering things. IF you look at the old SF games, they listed the characters birthdays with the day, month and year. As of 3S they stopped putting in the year, and now in SF4 a couple things seem to of happened;
-They've abandoned using years, but also avoid putting any distinguishing markers for the time
-Looking at the anime trailers they put out to hype the SF4 release some of us on shoryuken.com have speculated that they retconned parts of the series and have now merged part of Alpha 3 and SFII
-Street Fighter may have now adopted a sliding time scale like in Marvel and DC comics so things are ambiguous and the characters never really age past a certain point. For example, in the old canon SF4 should be taking place around 1995/96, but Viper's cellphone and car, etc all look very modern.
-I've also speculated for a while, but they most likely are going to retcon or alter SFIII - 3rd Strike. At the very least, they'll move it several years up instead of having things take place in 1998
Will Sakura ever stop using studend clothes?
I hope so, I hope she uses the outfit she has in her SSF4 ending aka the famous gym teach uniform that she wears in Ryu Final Manga. The funny thing about Sakura is that as of SF4 she's in her 20s but the developers said that she wears her old sailor outfit as her "battle uniform" for sentimental reasons and to have Ryu immediately recognize her. It's more than likely that the developers just wanted to hang on to her iconic look. Though with SF5, they're showing that they're willing to make drastic changes to the cast for the first time in a long time. Charlie's scarred (and synthetic skin?) appearance, Bison's white hair and new long coat. So there's hope for Sakura.