No. Theres isn't.
Graf_chokolo and marcan both have successfully disabled hdd encrytion on their ps3s, and since gameos uses ufs2 (correct me if i'm wrong), it is possible that in the future there may be a tool to read these unencrypted hdds.
But reading encrypted hdds would be a lot more difficult, I don't expect to see it happen, at least anytime in the next year imho.
STOP! Before you ask questions... READ the first post! RTFFP = Read The F*cking First Post
Yes, A 3.55 "jb" (cfw) is available, no >3.55 "jb" or cfw yet.
Yes, A 3.55 downgrade is available. But not to lower than stock firmware! (What it came with)
No >3.55 downgrade is out there yet.