Bevendre

“What’s there to be excited about with Ultra Sun and Ultra Moon?  They’re just going to be Sun and Moon with new Solgaleo/Lunala forms.”

Firstly, we know that the games feature an alternative story set in Alola, and there have already been new/altered locations shown off.  How alternative that is is up in the air at the moment, but may be either a completely alternate timeline where characters (and possibly cities/ecologies) are altered, or a story set in the future of Su/Mo much like Black 2/White 2.

Secondly, we know that the games are confirmed to have Pokemon that were not available in Su/Mo naturally.  It’s pretty much guaranteed that it won’t be limited to Ultra Solgaleo/Ultra Lunala.

Thirdly, we know that Gold and Silver are coming out on the Virtual Console ahead of USu/UMo’s release, just like R/B/Y came out ahead of Su/Mo and allowed for transfer through the bank, which was announced prior to Alolan forms.

We have 5 months before it comes out, and a lot of opportunity for info to come out.  Between the emphasis on it being an alternate story/timeline (coupled with the multiverse aspects that were confirmed in Su/Mo) and the Gold/Silver compatibility, I’m going to guess that we get more Alolan forms, possibly even of Kanto/Johto Pokemon that were in Su/Mo but may have evolved differently in this different Alola.

Patience, time will tell.  Worst case scenario is that we end up with the new Black 2/White 2, which I’d say were the best parts of Gen 5.