My concerns are the somewhat obsolete but useful software that I run, such as Microsoft Office (including Word and Excel) and early years of TaxCut, that I would like to keep using. I'm content with Windows XP because I find the more advanced versions cluttered (memory hogs) without real benefits. I don't want to have to re-buy Office.

TaxCut is only for the year issued. Unless you are doing tax returns for previous years, their value is limited. If you upgrade, either leaving them on the current system for occassional usage or moving them to a virtual machine on the new system would work.

The version of office you have may not work on a newer operating system. What I have done for Microsoft office is buy a new (unopened with key) but not current version off of Ebay.