It's weird to me that people complain over "old and ugly" interfaces. Consistency is worth so much more than fad-chasing. Learning something is more worthwhile if you are able to trust that it won't change underneath you. Take MS Office for example, I was made to learn how to use it in elementary school, we had an exam where we got a printed out page and had to reproduce it in an hour. This was supposed to be fundame…
It should be possible to have two separate open source projects. One is just extensive framework library with good API and the another is user interface. This would allow multiple separate UI's, web interface, command line, mobile, tablet, etc.