As development is driven by requests from users, and new versions get planned well ahead, I thought it might be worth starting a new thread for a list of "Killer Features" which would turn a good PIM into a market leading PIM.
I would like to see the following appear in a future version:-
History / Communications - a log of interactions with a contact (visit, appointment, call, letter, email, conference call etc.)
Email Alerts - allow an automated reminder of an event or task to be sent to an email address
More colourful themes - the default one is grey and bland (sorry Chris, but it is. It needs some colour). Colourful 3D icons for the modules, a little colour on the header etc.
A more configurable home page - column selectors, option to select events beyond the next 21 days
A new module to capture Medical information - this would allow you to log any medical info against members of your family (blood pressure, medical procedures, vaccination records, Doctor/Dentist visits etc.)
Integration to Google Mail and Google Calendars
...there may be more