It's really looking likely that Samoa Joe will be making his main roster debut soon. Joe has lost twice to Shinsuke Nakamura, and he could become a big top heel for RAW or SmackDown. According to what's being reported by The Wrestling Observer newsletter, there seems to be an idea that was pitched to bring Joe up to the main roster.
It's seeming like at this time Joe would be getting a huge push and to include him in one of the top WrestleMania matches. It's all up to Vince McMahon. If the idea does get approval from the big man himself it means he'd start at the Rumble or sometime shortly after.