Selectable exchanges: right now in, its early state, prices are set for end of day close aggregate across all exchanges.
Selectable currencies: Prices are in USD only. I would like to change this in the future if I get enough demand.
I plan on adding a wallet traker that would allow you to create your report based on the address entered and the dates you would like to see that transaction data. This would make doing taxes faster and easier.
Connect to individual exchanges to ensure you get a complete picture of your portfolio in a single view.
Add a wizard that will walk through all those wallet transactions, and help you determine a loss or gain, based on history, and produce the forms needed by your CPA or tax professional.
Add full blown accounts. This would provide history of all past forms filled and tax professionals will also be able to retain this history for their clients.
$10.00/year/person is all I ask to keep it free. If you do tax prep, I would ask $10.00/return.
All of these things require time and hosting space and API calls to several services, they cost money, support will be needed.