define('WP_POST_REVISIONS', 2);

Will do the same as the plugin.

now - imagine what havoc runs amok in WordPressMU when post revisions are left as-is. :D

I worked on a single WP blog that had default revisions applied for maybe a month or two. Over half the size of the database was purely revisions. Granted, this was a busy blog with multiple authors and posts per day, but also multiple editing of posts. All of them saved.

While I think it definitely should be optional, at least it can be easily disabled.