That's pretty close to what I would do with Sting. I think I pitched the program I would do between Sting/Undertaker in the previous thread. The only thing I might contend with is I think Sting would receive HUGE pops no matter if he cut his promos as a pseudo-heel or face. The anticipation of him actually coming and being in the WWE would go beyond traditional heel/face reactions I think. It'd be difficult in my opinion to book the Undertaker or Sting as either one, because fans would most likely pop huge for both of them. Kind of like Rock/Hogan.
As I mentioned earlier in the thread, the internets have mentioned that there are plans for Undertaker to face Brock at 29 next year, which would be huge considering their personal history. I posted the link that had the news along with the confrontation between them at that UFC event.