I'm all for it, even though I'd probably stick with the avatar I have, (it's taken me a while to decide and at times I went with no avatar at all). Looking at the avatars page, I can't see the reason behind some of the categories. Some of the avatars that need 300 posts are very similar to those that need 600, so there's no definition there. Overall they're mostly variations on a theme. Rank is not made obvious by these types of avatars either, they're not really a clear indication of a persons status (junior member/member/senior member etc). Most forums use ranking stars or pips for this purpose. Personally I'm not too interested in ranks or post counts and would prefer if member posts weren't counted at all, but some people do post with the aim of increasing this count.