Twitter is a fantastic resource. Because conversations are held in public, people are either kept honest or shown to be in denial! And now big names cannot avoid being part of twitter they can be held to account on it too.
This only works because there are not limits/restrictions on its use - content is not censored, managed or controlled - it is a peoples resource that the big boys want to be part of.
However, there is a risk (as ever) that once the big boys do become part of it, they will want to take it over and mould it to their will and to their advantage.
The BBC in particular are promoting specific hash tags for discussing programmes on twitter as they happen - this gives every twitter used equal access to be heard in real time, with no editorial control, immediately.
No waiting for 'points of view' to read out carefully selected week old letters in silly voices - peoples immediate, honest views as they happen.
On the internet everyone is equal just as it should be - the powers that be do not like their primacy being challenged, so it is for the common man to protect their rights from the attacks of the already privileged.