A couple of terms that appeared with 1.5 strike me as less than helpful for new users.
Theme: To me, "theme" sounds like skinning. What this terms doesn't convey is that it's a way of not only controlling the appearance of a site, but also the content.
Page: This is such a generic term that it really doesn't mean anything -- for instance, it doesn't make clear the distinction between dynamic and static.
Does anyone else find this vagueness irritating? Any suggestions for better terminology?