Nlite, although functional, is a dead app with no development or support. While devs of addon packs currently take care to keep compatibility with nlite, it is not unreasonable to assume that at some point in the near future, pack developers may choose to concentrate on RVMI with any nlite compatibility occurring as a happy accident. Additionally, any future msft patches for XP and by extension, any post SPxx service packs, will require SP3. This is because all versions of XP at SP2 and older are considered obsolete, out of support, and dead as of 01 July 2010.