No. Apple fixed the replay attack. As further proof that they don't mind jailbreaking, it took them two years to fix one of the most obvious vulnerabilities that any comp-sci freshman should know about.
The bigger problem is that once Apple releases 5.1 we will be stranded. If we encounter a problem with our jb, it will be impossible for us to restore and rejailbreak.
Save your blobs in the meantime............. I feel like I ready somewhere that tiny umbrella was working on a tweak that allowed you to install/ restore without the need of iTunes.................. Not too sure about where the source was but that what I remember.