I’ve not seen google wave yet, but here are my impressions based upon reactions from those who have.

Phase 1: HEY WHO HAS A GOOGLE WAVE INVITE THEY CAN GIVE ME?
This begging phase increases in popularity as more people actually get on the site.

Phase 2: THIS IS COOL, BUT WHAT THE HELL DO I DO WITH THIS ?
Turns out that the “I have something you don’t” novelty wears off quickly when people realise they didn’t actually need it.

Phase 3: HEY WHO ELSE IS ON GOOGLE WAVE ?
Belief that others may be able to enlighten them, and get them out of phase 2.

Phase 4: HEY THIS IS PRETTY USELESS.
Followed by neglect and forgetting they even have an account.

I’ve yet to see anyone praising google wave, but I’ve seen a lot of people go quickly through the above phases. I’m sure there are some people reading this through planet.*.com using it. Is it really “all that” ? Or is this google app going to be the next orkut ? (Remember when everyone thought that was the future? Ah, 2003 I miss you).

(This post isn’t actually me in phase 1. I couldn’t care less, and will probably skip straight to phase 4 when it goes public).