This would be great, see bugs http://bugzilla.wikipedia.org/show_bug.cgi?id=8339 and http://bugzilla.wikipedia.org/show_bug.cgi?id=6754 for more discussion about this. Maybe it will finally happen! :D
Also, whether you want to enable this or not, it might be worth thinking about building the system so that it would give you a warning on save that your text contains links to disambiguation pages, and displays some system message. I'm not sure a different css class is enough to draw most people's attention that are likely to generate these links.