If you're used to reading your comments and clicking the users name hotlink in order to send them an email you'll be in for a surprise now as the system will instead take you to their diary.
Assuming they're an authenticated (ie, logged in) commenter. If they're not you won't get a hotlink at all because, quite honestly, unsecure comments are just too much of a hoaxers paradise to allow you to really do anything at all with them except look at the comment itself.
Just in case anyone didn't want this change, I should like to point out that this, and many other changes, are being discussed RIGHT NOW on the Forums. Go to forums.hamiko.co.uk or click the Forums link from the frontpage and GET INVOLVED! (Or don't moan if you don't like things ;)). I'd like to get the forums buzzing though, there's a whole extra dimension to the site going on there!
Steve.