1. Can't handle large public waves. I tried joining the Lifehacker public wave. I could read it for about a day, but now it won't load or let me perform any action on it. Anytime I click on the wave, I'm presented with this message:
2. Can't read a wave without it being added to your Inbox. Any public wave you click on is automatically added to your inbox. It would make more sense to opt in to add a wave in which you haven't participated to your inbox. Any wave you edit should automatically be added to your inbox. This goes along with #1 as now I have a wave that cannot be removed from my inbox or marked as read.
3. Difficulty syncing waves. For awhile, I was receiving an error that I had "Unsynced Waves" that would stay for hours. I would have to close the browser and be warned that I would lose my updates. This seems to happen less with Google Chrome, and actually has happened less since I started using wave.

Now, I realize that this is just a preview of Google Wave, so bugs and scaling issues are to be expected. Even with these issues, I'm excited to see what Google Wave can become. I hope the team takes our feedback and churns out a much better and more polished product than we've seen so far. My wife and I are going to use it to collaborate on our plan for our upcoming Hawaii trip, which I think will be a good use case.

What do you think of Google Wave so far?

For more information on Google Wave, see the book being written by Gina Trapani and Adam Pash (of Lifehacker fame). Not only is it a complete guide to Google Wave, it's an experiment in tech publishing on the web.