We don't know yet. Hopefully they'll allow it though. At this point, there's so many Pokemon out there, it'd be very difficult to force people to start over (although then they could release 3-D remakes of everything from Red/Green to Black/White to really milk their fanbase).
Not yet. But since DS games can connect fine to 3DS, they would have no excuse to not allow transfer. I mean heck, they actually made a 3DS app that can recognize the presence of a DS game http://tinyurl.com/d8fsfhn ,but they won't do the same for X/Y?
Im sure they would LOVE to see their profits drop if they block compatibility to older games right?
Freiza may be cool, but his brother is..... COOLER(get it?) 3DS FC:0645-6947-9076