Until fairly recently, the originator had their post count show. In most instances, I seldom bother, but when it's their first post, I, and several others, like to extend a "Welcome to the Forums."
Have just noticed that there are many recent posts, where the poster's "count" is no longer shown.
Not sure if we can infere that it's their first post, or perhaps the post count has just been dropped completely, though I do see it for many posters and in several threads?
As a for instance, in this thread: http://forums.adobe.com/thread/1030392?tstart=0
the OP had no post count showing. Now, with their Reply, it shows "2 Posts," so that WAS their first post.
I agree that the information would be useful. One could, for example, see 1 post, join date today and say things like "welcome to the forum". Note that I had typed this before reading the other responses.
That said, you can, of course, hover over the avatar and get all the info you could ever want.
You can hover over the avatar to see the Profile, but that is not the ultimate way. Folk, such as yourself, who post excellent replies so often, would be better served, just seeing that info with no work on your part. Little things can make it much easier for those, who are mainly in the forums, to answer others' questions.
Just my way of thinking.
PS - for now, I will assume that no Post Count = First Post, and proceed accordingly.