Sorry, but a new UI toolkit should look pretty. Maybe some of those controls looked okay, but if so the screenshots didn't do them justice. I wasn't particularly impressed. No reason to use these over the other toolkits, far as I can tell.
The industry is desperate for a good cross-platform GUI framework. If you manage to solve the problem I guarantee you a very comfortable living and a world-wide fame comparable to Guido's.
Do a google search on just about anything software-related and start calling these companies who sell millions of dollars of Windows-only software offering them a quick and painless transition to cross-platform GUI for, let's say $1M.
I can't even begin to describe the desperation I've seen at various companies I worked for. There are trillions of dollars worth of Windows software that is much needed on a Mac or Linux and vice versa. I once worked at a startup that lost a contract with US Navy worth more than all our previous revenue combined just because we were Windows-only. And at my current company our #2 support question is "When's Mac support coming?"
You used to be able to do this, I tried once, with Delphi and Kylix (the linux version of Delphi), the only problem was that the Delphi ecosystem encouraged third-party widget/controls, many of which were tied to specific versions of Delphi and only ran on Windows.
