As an AI language model, my responses are based on general knowledge and I do not have real-time information on specific previews or teasers for casino games this year. However, I can provide you with a list of popular casino game developers that often release exciting previews or teasers for their upcoming games. You can stay updated on their official websites or social media channels for information on new releases:
1. NetEnt
2. Microgaming
3. Play’n GO
4. Yggdrasil Gaming
5. Betsoft
6. Evolution Gaming
7. Big Time Gaming
8. Pragmatic Play
9. Red Tiger Gaming
10. Blueprint Gaming
Keep in mind that the excitement surrounding upcoming casino games can be subjective and dependent on personal preferences. It is always recommended to follow official sources or platforms that cover casino gaming news to get accurate and up-to-date information on the most exciting previews or teasers for new casino games this year.