This is fantastic news! I've always felt that once Paramount green lit TNG in HD they would eventually get around to DS9 and VOY. Star Trek is still a big cash cow and with the new Star Trek movie out (or just about out for some), it will only generate new interest in the franchise.
The fact the the majority of CGI is saved is amazing!!!!! I feel as though the technical staff on Star Trek had a foresight that the Producers and the studio lacked!!!
The good thing about DS9 is that the show actually didn't start heavily into CGI until the 6th season. The first 5 seasons were largely model work (even the big Klingon battle in way of the warrior). And the station itself was always a model they only CGI shot of deep space nine is in the final second of the show where Kira and Jake look out the window and the station fades away.