It is always the seiyuu and seifuku jokes that I get the most satisfaction out of in Hayate no Gotoku. I noticed these the first time I watched 41, but was more interested in the Hina aspects, that I did not think too much about it. Watching it again though brought about a healthy laugh.
Kamyu from Utawarerumono
Maaka Karin from Karin
???
Sonsaku Hakufu from Ikki Tousen
The Kugimiya Rie and Yahagi Sayuri jokes were fairly easy to spot. Asano Masumi’s joke, I originally thought was Yuma from Joshi Kousei because she wore the sweater, but the gloves gave it away. However, the outfit that Miki is wearing baffles me. I am not all that familiar with Nakao Eri, and even after looking at her ANN page, I am not sure how that joke works. It looks like a plug suit, but at the same time it is different. I swear I have seen it before…
Instead of Nagi getting a jab in there, I would have rather have seen Hina dressed up as Wilhelmina, complete with ribbons galore. Hina taking on Yukiji? The Interperter of Condolence vs. the Manipulator of Object? Novel ideas indeed! 
I just downloaded and watched this episode. The first one I’ve ever got to work! Already 41 eps. on this series? well, I read the manga, so I know some of what’s going on. The video quality surprises me; very nice!
i really really need to get caught up with this series
@Krazer: I thought that too, but I never finished Zegapain, so I wasn’t sure.
Miki seems to be Dita from Zegapain. Nothing else really makes sense. :p