There is a new image of unit listings from the upcoming Tyranid codex floating around right now. These are most likely coming from the January White Dwarf and originating over on 4chan, but have found there way into several forums. Shown in the pictured leaks are of course rippers, and Hormagaunts.
Here is a link to the leaked image.
http://www.lounge.belloflostsouls.net/showthread.php?33545-Tyranids-Rumor-Roundup/page85
My favorite part of this is that rippers can purchase deepstriking. Literally the sky is falling.