1. The greetings/wishing message: Congratulating a person so that others also know through gtalk status message, wishing everyone on festivals so that people read the status message and get the wishes! Same for the birthday or wishing for other reasons.
2. Quotes message: The kind of quotes a person puts as status message reflects their personality. I have read quotes on love, passion, inspiration, faith etc. When I keep quotes as status message, I always give the name of the person who spoke those lines, i.e., I give the source which is important.
3. Comment on other's status message message: The problem with this one occurs when the person who's status message is commented on, goes offline. People like me browsing through the status messages have no idea what this person's talking about. Mostly these messages have this line, "I agree with
4. Humorous message: Some joke or one liner.
5. Advertising message: This message shows links to their or some other's blog or some other interesting webpage(s) which may contain jokes, some news article, some online game, some interesting orkut/facebook profile or some interesting image or video on youtube.
6. Personal condition message: This message tells about the mood or state of mind of the person, which the person choose to share with his gtalk friends.
7. Comment on something done lately message: It is something that the person has done lately like watching a movie and could be a comment on that. People sometimes only keep name of the activity or the movie seen and expect that to convey everything!!
8. Current soundtrack message: The currently played song is displayed on gtalk as status message but only if winamp or windows media player is used.
9. Miscellaneous message: The type of messages that I haven't read till now.
Facebook introduced discussions on status messages which is an interesting activity. The status messages on facebook also, I presume, fall under the categories I discussed above.