One critique I've heard about Model-Glue is that there's no easy way to create "modules" of functionality that can be "dropped in" to existing applications.

I mean, wouldn't it be nice to write a forum app, and then just say "add this to my Model-Glue application?"<p>[<a href="http://www.firemoss.com/blog/index.cfm?mode=entry&entry=B9829385-3048-55C9-430D3F873479C35B">Read more on Joe Rinehart's blog</a>]</p>