Hi, 
I am developing a site using PW and I am excited about the prospects. 
I was also considering getting involved in updating another site: 
geograph.ie 
It is obviously a bit dated.  My initial thought was that it was very Drupaly looking and that migrating to Drupal might be a good idea.  I have started and then stopped a number of projects using Drupal and I am a bit disillusioned with it's inherent awkwardness.  It always feels like you are one module away from getting something done. 
Anyway, how would you approach moving this to PW ? Any quick ballpark figures on time or expertise required ? 
thanks