In my personal opinion, probably yes. But right now, I personally think that the risk is pretty moderate. Here are the main reasons:
1) A source of danger in the past was a phenomenon that I will call "rumor rush". The atmosphere around most companies was a silent one, interrupted once in a while by a thunderous press statement. And everyone in the press was in the "wait" mode. That explains why all press journalists were like sharks. At any sign of a new rumor coming, everyone started to analyze it, enhance it, speculate about it, use it to generate new rumors. After a while, things started to settle until the next rumor. Even more, this "rush rumor" behavior caused a vicious circle, because employees were then discouraged to discuss publicly about almost anything, based on the fear that anyone could cause the next rumor rush. And this fear decreased the information bandwidth which increased even more the waiting tension.
Nowadays, there is a constant level of buzz around blogs, so the "rumor rush" phenomenon is probably gone forever. If you want to find the latest news, rumors, projects at Microsoft. look no further than Channel9 or MSDN/Technet blogs. The fact that the "rumor rush" period is gone is proven by the fact that less and less posts on http://blogs.msdn.com are Slashdotted today. It's the natural evolution of things. The fact that Microsoft bloggers are so open is no news to anyone...
2) Another problem in the past was the fact that an employee was not supposed to say anything about things not in his domain of expertise. The risk was, obviously, that you say something wrong that can confuse customers. Or, you might touch a sensitive area where some team wants as much as possible to avoid discussions due to problems in the past.
But, today, the blogging community has a self-regulating mechanism. If you say something that doesn't make any sense, then you can be sure that the other bloggers will be the first to blatantly correct you either in the comments area, or better, by posting articles saying that you are dead wrong (it never happened to me... yet :-). Therefore, the risk of causing a major cataclysmic event through a bad post is very low. Bloggers tend to be smart persons, generally.
3) Also, there is also a problem of firing people, due to the fact that the said something wrong. In the past, most companies carefully forced its employees to be silent specifically to protect them. Naturally, you don't want to lose important people just because they caused a stir.
But, these days, the rule "Be smart (translated: don't be stupid) when you blog" is understood better and better every day, both by bloggers and their mother corporations. Even the dry, soul-less LCA departments are now realizing the power of sincerity, know better how to handle this flux of new blogs, and are now more tolerant on minor mistakes.
4) Finally there is the intellectual property issue. This issue is very serious these days (as in the past). but, as I said above, people have learnt in the last years what is good and what is wrong. It goes without saying that you should not post about confidential information. Or, about stuff that is sensitive to other companies, especially competitors.
But, still, today you don't really have to put huge, artificial, disclaimers in legalese in every new post. And I think that, in general, blogging made people even more aware about IP issues...
Any opinions? Am I dead wrong? :-) Let me know in the comments section...