Even though McGregor isn't

very good in this one (Colin Farrell would've been a better choice in my opinion), it all goes to Polanski's skills that the movie is so strong. He chose a very intriguing script to work with, Edelman shot it coldly and Desplat composed a suspenseful score. Besides, the design of the house is very tasty.

Some people have problems with Olivia Williams's performance, probably Tilda Swinton (originally intended by Polanski) would have been better, but surely not much better.
It's also one of the Brosnan's best roles in recent memory (in "The November Man" he gave an equally great performance).

It's hard to find (aside from Fincher's) a truly intriguing and masterfully done thriller nowadays, but "The Ghost Writer" is one of them few.

Hitchcockian indeed.