I have had no problems whatsoever with my B9180 after upgrading to Snow Leopard.
Printing from both PS/CS4 and LR2, there have been no issues with colour shift, profiles disappearing, etc. However, I am using only HP paper and the profiles that are included with the HP driver; no custom paper profiles. Also, printing colour charts from Preview with printer-managed colour gave identical results to what I had before Snow Leopard.
Tom.