Sorry. Seeing blog posts with titles like Memo to mainstream media: you don't get to blog has the same effect as seeing signs that say 'wet paint'. You have to go and touch it, even though all it achieves is demonstrating that the paint is - guess what - wet.
In fact, the discussion over at Corante, linked above, is high calibre, even-tempered and covers most of the points. But as mainstream media blogger I naturally have a jam jar full of ha'penny's worth to throw in. I will try to be brief.
Condensed, the argument against MSM bloggers appears to be: We the real bloggers are having a conversation, you the media are selling a commodity. Dialogue and sales are different modes of communication. Go away.
That conflict definitely exists, although I think there is a bit too much suspicion of the motives behind media blogs. The faint ripples created in the blogosphere by hacks like me dipping our toes, diving or belly-flopping horribly into the water are no threat to the integrity of the blogging community as compared with what will happen when the big media companies decide - as they probably will - to quit trying to join 'em and start trying to beat 'em.
The distinction that matters is between active internet use - writing your own stuff, linking to whatever seems interesting, building your own networks - and passive internet use - click-only browsing and being entertained, reaching for the keyboard only to type in the credit card details.
Eventually the big media companies will realise that they can package and sell the interactive feel of blogging, but in artificially constructed 'safe' internet reservations. You give people super easy to use tools (and I mean easy like TV remotes, not easy like Moveable Type) and you let them build 'blogs', except making sure the currency they are exchanging is your paid-for media product - music, films, pop videos - instead of free ideas.
Watch and see what happens to (now Murdoch-owned) Myspace.com.