You forget the threads on Billy’s message board can be read only by registered members. Registration costs nothing, mind, but perhaps a quick cut/paste of the relevant posts would be nice for those non-fans who don’t want to bother with the process?
As to whether Udon will do the next Shi series, Billy met with Erik and they had a quick chat about it (I was standing right there, so I know it happened). The results of the meeting seemed favorable, but don’t get your hopes up just yet – Erik met with a lot of people during the convention, and I think it’s a safe bet to assume Udon’s plate is quite full for the next few months at the very least.
As much as I love both Street Fighter and Shi, I don’t think a crossover would work. While a couple of the characters have something in common, I think the universes are too dissimilar for it to work credibly.