The widget toolkit Qt is fully themable. By default Qt tries to look native (and boring), because it's commonly used for serious user interfaces such as for industrial systems. But you could use another Qt theme, or design one yourself. On at least Linux desktop environments based on GTK or Qt you can change the global theme of your desktop and Qt will pick that up.
As gmaxwell says there is a lot to designing a good GUI apart from it looking 'pretty'. Safety and usability is a first concern.
In general everything is possible. This is an open source project. If someone contributes towards making it look more "pretty" (and other people agree - I don't think a my little pony theme will be accepted as default), it will. It won't improve by just waiting, for any amount of time.
Edit: Also, going over the top with a 'pretty' interface means committing to redesign every two years, as the fashion trends change quickly and what looks exciting at one point looks ridiculous the next. Native widgets don't go out of style because they never were in style.
As gmaxwell says there is a lot to designing a good GUI apart from it looking 'pretty'. Safety and usability is a first concern.
In general everything is possible. This is an open source project. If someone contributes towards making it look more "pretty" (and other people agree - I don't think a my little pony theme will be accepted as default), it will. It won't improve by just waiting, for any amount of time.
Edit: Also, going over the top with a 'pretty' interface means committing to redesign every two years, as the fashion trends change quickly and what looks exciting at one point looks ridiculous the next. Native widgets don't go out of style because they never were in style.
Yeah it looks pretty boring. More like some gray accounting software. It needs more bling-bling in my opinion. I think it should be golden, like the Bitcoins themselves. And a nice ka-shing sound when you receive a transmission. Maybe some rap-music in the background.