You can prepare for the future and continue to use FrontPage or its successor Expression Web. Do this by removing from your pages the features that require the FrontPage server extensions (shared borders, link bars, hit counter, subwebs, etc.)
This page has a list of features that require the extensions
http://support.microsoft.com/kb/281532/EN-USThe only FrontPage specific features I use are Included Content (does not require the extensions) and the FrontPage forms. It will be easy to replace these two features with their PHP equivilents when the time comes.