I have been playing with it and I think it's awsome. You can now run it without MDI windows. It's fast, looks nice, and I haven't fount a page it will not load yet. Very nice.
 
I thought I should edit this a bit. You can also run it in MDI windows. We now have a choice.
 
Ge0ph

I'm using the Opera 6 beta too and its pretty good. It has a couple of annoying problems like the page loading bar occasionally disappearing before the page is loaded and a new, funky way it loads images but other than that its great. Although the option exists, I for one won't be turning off the MDI any time soon since thats one of the best features of the program. Code handling seems to have taken a small step backwards as well. A menu at a site I visit (which never worked properly anyway, the options would scroll down but wouldn't scroll up again) is now completely messed up. I hope they get that sorted out although if it involves breaking Operas standards compliance (the absolute est part about the program, none of that M$ garbage HTML) I won't have a bar of it.