Just a few things I thought of that I'd like to see.

-Allow other denominations besides just BTC (mbit, bit, etc)
-Enable the "Add this wallet to the ignore list" feature. I see it is there but just not enabled (unless there is some configuration I'm missing).
-If possible, a way to query specific blocks / information in the blockchain. This would be really nice to check transactions without needing to go out to a third party such as blockchain.info
-A way to view the priority of a transaction you would be sending. Idealy it would give a notice if the priority is high enough that the transaction can be sent with no fee