The January 2010 issue of Kadokawa's Nakayoshi magazine has revealed that the popular shojo manga "Shugo Chara" will be coming to an end after three & a half years. The final chapter will run in the February issue, which actually goes on sale on December 28 in Japan.
Considering how popular & long-running the anime adaptation of the series has been, it was easy to get comfortable & assume that Shugo Chara would simply always be there. Not every anime get greenlit for 100+ episodes, after all. Those that usually do are stories that tend to go on for years, if not decades. But that just goes to show how popular & successful Shugo Chara has been for Peach-Pitt. Peach-Pitt has had several other popular series in the past, including Dears, Rozen Maiden, & Zombie Loan. But of course all of those came to an end after a couple volumes. Some fans thought that SC would be a title they'd stick with for a very long time, but it seems even this must come to pass. As for the future of the anime, that's hard to say at this point. More than likely, the current third season will be its last. I love this series, so it'll be sad to see it go.
Source:
http://www.animenewsnetwork.com/news/2009-11-29/peach-pit-shugo-chara-manga-to-end-in-japan-next-month