Quite. Bullying is repulsive behaviour, and I see absolutely no reason why the law shouldn't potentially be adjusted to better protect people from its online forms.
Technology is constantly changing and it's the duty of law makers to protect the people from new dangers that arise from those changes. You can't have static laws in a technological world, it's moronic.
I'd argue that there's far greater historical precedent for law changes being more useful to society than harmful. Of course there should always be caution in drafting new laws, but to go to the extreme of refusing change is crazy.
Perhaps, but what form would it take? And what about current legislation doesn't already have these protections against harassment and threats in law? As I understand it, the Communications Act 2003, Protection from Harassment Act 1997 and various racial / sexual harassment related legislation offers protections / recourse against such communications, whatever form they take. So yes, including Twitter. But my main apprehension about anything new is putting something technological in that could be abused; the ISPs and Government's recent rumblings regarding opt-in / default-on filters has stimulated some debate in this area and I don't believe the concerns there are completely unrelated to concerns here.