I maintain that the reason that the Romulan in that scene was only ridged to clearly state that he was a Romulan and cast aside any doubt in the minds of the viewer. Whether or not the other ones we'll see is up in the air, but at least these were fairly understated, not like the hideous ones used in Nemesis.
Sorry, I missed your other post. I read this thread first. I think that they could have made the same point with the classic TOS uniform (which is similar to the one used in this episode, so I've little problem with it) and a brief mention that "Romulus will not be pleased with your failure."
In any event, now that a Romulan has been shown with ridges, I think we are likely stuck with them. I can't see
Enterprise suddenly abandoning ridges now that they've used them.
Of course, Trek 5 and Trek 6 used Romulan looking Romulans, and I'm fairly sure both were made after TNG had started the love affair with "all aliens -- including Romulans - have ridges". I'll continue to hope.
-S'Cipio