I actually haven't missed this too much. Perhaps make those two bits of info fade in and the user info block expand vertically on mouseover? One good argument for *not* adding that information is so that the user info block does not get any taller and thus waste vertical space when the user posts a short reply. Another thing is that that information is available in the membership card overlay when you click on a username/avatar.
I like it without the post count on the thread view. It's a pleasant change
For one it will prevent people from posting nonsense for the sole purpose of increasing their post count and would allow new members to "blend in" easier. Maybe feel like less a of sore thumb to the community. I know the latter has been true for myself.
If it must be added, then an on/off button would be good too