I've actually heard from various different sources that 3-piece suits are coming back in style. You can actually purchase a replica of the Goldfinger suit here: http://www.magnolicl...hiers-p-41.html
I believe they never left style. You just need to be careful with a three-piece cause it's a little too formal, so it doesn't fit everywhere.
... and it doesn't fit everyone. You have to be tall and lean to wear that. This looks just awfull on the guy in the pictures. Waistcoat goes too high; last button should be loose; jacket is way too long; etc.
Right! I forgot about that! If your belly is a little big then the three-piece is not for you.
I'm lucky though cause I'm tall and lean as Messervy said. Thank God!

You're right on the "formal" side of the 3-piece. I wear a suit everyday for work, and although I own 2 3-piece suits, I rarely wear the waistcoat. It would indeed be percieved as overdoing it. I could envisage wearing them for a reception or a high-level meeting, but not for day-to-day work.
That being said, I happen to have colleagues wearing a tie with a short-sleeved shirt ... yuck!