If its warm and raining, get wet.
If its cool and raining, wear a softshell.
If its cold, like real cold, and pouring, wear a waterproof made from eVent. In order to not sweat to death while wearing a waterproof shell you must dress light, and have pit zips, and as much active ventilation inyour jacket as possible, and it must be cool/cold out.
eVent breathes twice as well as the best goretex. There is a lot of research on it. Heres a couple links, google will find you lots more.
http://www.climbers-shop.com/Waterproofs.aspx
http://www.spokesmanreview.com/sport....asp?ID=193267
http://www.prolitegear.com/cgi-bin/p...xdpy/kb/00029/
Showerspass Elite jackets are the best I could find for cold wet weather. A lot better than goretex.
J&G also makes a jacket that a lot of commuters here like and for a great price.