I think popular blog posts will still hold the water. They cannot change the basics on which their PR formula rides. "The Links"
Best thing is to let them speculate.
Yes if we have a testing domain on testing server then testings won't hurt
But for main sites I think the advice given should be taken after giving some thoughts. Who knows maybe someday google might again change their mind. :D
---------- Post added at 10:35 PM ---------- Previous post was at 10:29 PM ----------
Update :: Some afterthoughts ::
Lets assume this same page/thread we are discussing this issue.
Cash balance (Check) << This link gets same weightage then the links in my sig?
The donate link also gets same weightage?

I don't think so

The algo can't be that bad

There are millions of posts on NP itself and all postbits link to Donate and Trader rating pages. Pagerank should be blocked from passing on there. But Agreed it might be a tool for someone else who might be mis-using it. This is going to be great food for thought for all bloggers for quite a while.
Further reading resources :
Why Listening To Matt Cutts Is A Bad Idea » SEO Chicks :D