Anyway, a few thoughts...
1. I find the event planning stuff to be kind of stale. Like maybe it will be cool this time, but so far it's part of every demo and concept around AI assistants and it's never ACTUALLY been cool. I wish this was trying to be cool in a new way.
2. The turn-taking for voice input looks kind of awkward. I get why it has to be that way, and there's not really a better solution, but... well, maybe it would be possible to use visual output and voice input, or generally make them complement each other. Many details are better to show visually and can be tedious to listen to.
3. I like the patient and attentive secretary model more than the turn-taking chat. The confirmation turn-taking is a trust exercise (did the AI _really_ hear and understand what I said?) but I think there's other ways to handle that trust. Like being more trustworthy (modern non-streaming speech recognition works really well!), making things easy to undo, or detecting unlikely commands and require verification.
4. For example, when reviewing a to-do list, I'd rather it show the list and I can just say "yeah, I finished item 1 and 2, and I was able to pick up milk but there's still some other groceries I need to get for tonight" and have it complete and revise entries based on that.
5. Generally to-do and task management is 10x more interesting to me than calendaring. But you should have a theory, not just be a layer over something else. I should be able to break down tasks, complete subtasks, identify partial completion and have it identify the remaining portions, get suggestions on breakdown, get advice on which tasks to complete when, etc.
6. Another interesting thing would be a kind of personal database. I would love to be able to unload a lot of information from my head and know that it will be put someplace where it can be meaningfully retrieved, combined with other data, etc. Like if I have certain bill payments or house maintenance I want to remember or something, I don't want to turn that into calendar items. Lots of them aren't even fully articulated, or the structure will emerge as more information becomes available. But I want to get started before I have carefully defined the task, and an AI assistant could do that.