It was noted in the release notes that the "Altiris HTTP" service, which the task servers used in NS6 is no longer supported. I know this is part of the site server functionality.

hmmm if so that kinda sucks for me, I love the new stuff in 7 and really want to convince us to upgrade, but we have over 450 package servers that are not our teams specific servers, and convincing someone to purchase 450 new servers just for us as file shares basically will be a very tough sell.

Well I have 7 installed in a test vm just checking things out.  I'm not real familiar with most of it, so still just trying to find stuff and configs etc. 

But I did notice that when I choose a machine to make it a site server that if it doesn't have IIS the Task Service is greyed out, but it did let me choose package server.  I can't seem to get it to install on the test package server but maybe I'm just not doing something right or something isn't configured in general.   Also I noticed in the package service config it has publish http codebases (if IIS is installed) as an option.  Not sure if this is legacy or what, but it leads me to believe that if just using the package service IIS may not be required.