There are many - in priority order I would say:

• the main client apps (damus, primal, amethyst) should also become remote signers - this way users only have to download one app to easily reach all the others without having to paste their nsec around
• the zap spec (or an alternative new nip) should be more flexible - right now its very opinionated as a reaction event and it's hard to get creative with that
• more adoption of the generic comment proposal (we plan to support this soon)