To me, the interesting thing about both the twitter feed (which I haven't looked at yet) and the blog (which I have) is that they are both* new. The first content on the blog is dated 17th August which was last Wednesday. So, what has prompted Ridsdale to take time out from all of the other things he is doing to set up both a blog and a twitter account? Why does he need these communication tools now?
The blog seems to me to be angled towards giving his income-generation stream as a public speaker greater visibility. It's almost as if he knows that he is going to be in the public spotlight and, perhaps, in need of personal income, in the near future. Mind you, it has to be said that the set up of the blog and the quality of the writing on it is really rather rubbish for someone who seems to be so concerned about their image and the way they are portrayed in the media.
As Gareth pointed out, and as the first comment posted on the blog indicates, the entry on retail banking does come across as if some bank has recently made his life difficult by not giving him something he wanted.
* edited to add that the twitter feed isn't new but dates back to May, although it has hardly been used - 3 tweets in May and then 2 in the last week.