You're thinking about the 'Yamato Nadeshiko' topic ?
Mah I can't say whether there has been an increase thanks to her... I certainly can't say there's that many characters similar to her, the only other girl I know that has her tongue is Yozora from Haganai.
This Spring might be the exception though with this many black hair girls of high quality, heck that crossover fanart I use for my Sig is not the only one with similar theme out there so our Japanese friends seem to notice this as well.
You know, your sig and avatar makes me realize that Hitagi Senjougahara's popularity has really influenced things a lot. Her character style is being seen a lot more - She probably also inspired Akemi Homura some.