How can we recognize a 'real' update?

[web_24_7]

It seems across all boards that many think an update or even new google engine will occur in the comming days if not weeks.

On the actually happening of an update do the top ranks actually change, like the top 5 for broad keywords or are they entrenched?

Will a google representatives actually make a comment when its happening or about to happen.

They could say in one week itll update, so clean up your act! Its like drivers flash their lights to warn other drivers of speed police - it gets people to go legal.

Also will [rankpulse.com...] actully show this or is this a false tool like PR?