Here are a few more excellent B2B blogs that I find useful and excellent. See my two previous posts listing other top B2B blogs here and here.
http://blog.eloqua.com/
http://www.dmconfidential.com/
http://www.twistimage.com/blog/
http://www.chrisbrogan.com/
http://www.copyblogger.com/
And I mustn't forget this one:
http://www.feedthebeast.biz/blog/