I wouldn't say so. I believe one of the cases in the States actually involves a couple of guys who were working for Dean. I know that there are splits within all three of the major parties here about this issue, although all parties have an "official" policy of disclosure.
The blogosphere is a strange place. Some bloggers hold to journalistic standards like checking facts and sources. Those generally let either let their biasses be known or stick to hard news. Some (for both sides) lie and slander and misrepresent worse than Fox News. In between there are many shades of grey and you never really know what you're reading.
It would be nice if there was some kind of rating standard that could be applied, but how the hell do you do that on the internet? I think the best that can be done is to make campaign and election laws that require campaign workers to disclose who they are working for.
That way people would, at least theoretically, know if they were reading official campaign spin or just a normal blog.