Google displaying longer descriptions in the results pages

I’ve noticed that the longer the search phrase you use the longer the description Google displays in the SERPs

Long Description in Google SERPs

Are these longer descriptions always displaying like this or is it just another Google trial?

Do others see these longer descriptions in Google results pages or only a limited number of users?

Update:
Looking in to this more, the whole SERPs layout seems to have changed slightly. I am getting longer descriptions and a clearer fresher look.
Have Google changed the fonts and colors slightly in the SERPs too?

Update 2:
Looks like this was rolled out in 2009 – http://googleblog.blogspot.co.uk/2009/03/two-new-improvements-to-google-results.html – Has it recently been switched up again?

Update 3:
Titles appear to vary in length depending on which browser I use and I also wonder if the results are slightly narrower?
Are Google trying to make more room on the right hand side of the SERPs?

Screenshot taken using 1600 x 900 screen resolution.
extra space