As you'd expect dataminers have been looking into the code of the Street Fighter V beta on PC that was released over the weekend. Their findings as detailed over on NeoGAF, suggests that Dhalsim will be playable in the final game along with two new characters thus far only identified by their three letter combinations FAN and TUT. Meanwhile, data pointing to Alex and Ibuki are likely only indicative of them being used in the background.
Of course, with Capcom's strategy for Street Fighter V being what it is, you'd expect background characters to step into the limelight as DLC at a later date.