They could very well be hiding M2 as the developer, or some entirely new team we've never seen before. I think that at least Taxman is involved, but not due the unnanounced status of the developer. If we all limited ourselves to only basing our assumptions off that one unknown variable, then we'd all be in a three-way tie for last. Potentially even a four-way tie or higher, but never lower until a bit of info arrives to cross out a candidate. The omission provides us with absolutely nothing. So why do I still think Taxman is involved then? The Retro engine is why. It is not yet confirmed to be what the collection will run off, but if we consider all the extra features and the titles included, then the Retro engine takes the gold while the Ages engine takes the silver. Retro takes the lead for two simple reasons: CD and S3K. Yes, M2 could have to take on the unfortunate task of porting CD alongside 3K using their Ages engine, but it'd be far more likely and practical to see about contracting Taxman first. All Sonic 1, CD, and 2 would need are the promised extras and optimization for consoles, while 3K would need to be built. M2 or anyother developer would have to start from scratch, whereas Taxman would be resuming construction from an existing base. Having Taxman on board would basically guarantee a quicker release. S3K is to blame for keeping the developer a secret, and I'm positive the team won't be revealed until they have footage from its port to show off. So once again no team can be ruled out yet, as we simply don't have enough info. I don't think Sega/Sonic Team are witholding information now in an effort to generate guaranteed buzz closer to release. I think they're just waiting to see a functional product.