A nice, quick and clean way for companies to use Twitter, particularly ones where a few folk have twitter accounts, but where previously there was no co-ordination, and only one poor sod was tasked with updating the twitter feed. I say a definite YES to this.
And that's because Twitter, when used to engage and not simply to broadcast, reveals the person behind the politician; their principles, their passions, their personality. It's the authentic voice that comes through, of the MP and in aggregate, of the Party. People appreciate that.