I think the explosion in interest and all the new software around GenAI owe their success to NLP advancements (coming from an NLP background myself, I may be biased though). I think the best projects are those pushing the frontier of NLP and sharing the learnings with the world:
https://huggingface.co/mistralai/Mistral-7B-Instruct-v0.2 - Mixture of Experts model like GPT-4 but this one is open source doesn't cost an arm and leg to run.
https://huggingface.co/mixedbread-ai/mxbai-rerank-xsmall-v1 - This is a very recent reranker, we will probably try it out. It's really nice that it's open source and small enough to run on CPU. I think an overall trend of the space in the next years will be to maintain/improve performance while shrinking the cost and hardware requirements.