Great point, but it is also quite easy to go too far in trying to factor out features that one should just build. I think we need a matrix equivalent to the recent xkcd <a href="http://xkcd.com/1205/" rel="nofollow">http://xkcd.com/1205/</a> to inform decisions on when finding, integrating, and adapting a certain "factored out" service or feature is simply not worth the effort...