hmm. ::xowiki::Portlet is gone since a while (at least two years). What version are you using? if you have a newer version and not modified weblog for this package instance, you can delete the weblog page from the content repository and it will be recreated on the next weblog request from a more recent version.
In general, weblog is used for listing of pages belonging to tags or categories. If you do not want weblog at all at your site (openacs instance), delete the weblog.page in the prototype pages. if you have some package instances wanting weblog and some not, currently the best way is to subclass xowiki, and provide for the subclass a smaller/different set of protoype pages (see e.g. the s5 package for such an example).
