I have a feature request that would make your application very usefull to me and probbably many more people.
Have the ability to add companys and then assign users to companys. Projects then fall under a company making administration much easier for consulting companies like mine. This one doesnt seem all that complicated and is the highst on my priority list. I currently use bugnet for our company but without this feature I will probbably be switching becuase its just too clunky to use and manage for us.
If above is done the other really nice thing would be to have the ability to send items as tasks to exchange so they pop up on people's calendars.
Also as a side note if you need help developing said features let me know. We are a custom programming shop that specializes in .NET and would be willing to help implement the features becuase I do love what you have so far.