Russ,
We don’t provide upgrade wizards but what you can do if you are feeling hardcore is to trick MyEclipse into thinking you removed Struts capabilities, then simply re-add Struts 1.2 capabilties. You might want to clean out the old libraries from your /lib dir before you re-add though (as well as TLDs) to avoid confusion. Also note that your taglib URIs will change between those two versions if you are using the default ones (jakarta.apache.org/struts –> struts.apache.org/tags or something like that).
To remove struts caps, switch to navigator view and erase your .mystrutsdata file and then open your .project file and remove the easystrutsnature at the bottom. Save all these changes and close and reopen your project, now you should be able to re-add Struts capabilities.