I don't think so. Haven't tried it myself but I can tell you that I had a problem with compatibility between the 2005 DTS add in and 2000. When I modified a script with the add in then ran it on 2000, parts of it didn't run but didn't give me errors either. I had to go back and edit the package in 2000, touching each step and delete the revision history before it would work.
I never had errors when editing the package in 2005 or running it in 2000, it just didn't work right. I deleted the add in and went back to using Enterprise Manager to maintain my existing packages.
T