I tried the new Yahoo! Mail today. I switched back to "classic" mail immediately. The first issue:
There seems to be a screen resolution problem. Your screen resolution is set below our minimum recommendation. When it's set under 1024 x 768 pixels, the all-new Yahoo! Mail won't look as good. You can continue with your current settings, but you won't be able to enjoy the full effect.
Really? My netbook has a 1024x600 resolution and I can go to 1024x768 with a scrolling desktop. The scrolling desktop is annoying and makes things unusable. Applications should scroll, not desktops.
The new mail does not render well in Opera. I use Opera because I think the scaling feature is superior to Firefox, IE and Chrome. It is nice to be able to size the contents of the web page to 70 to 90 percent while maintaining usability and readability. That is a nice feature when you have that 1024 x 600 netbook display. At 100 percent it looks like crap and does not get any better at zoomed levels.
I tried using Firefox and IE to see the full effects I should be enjoying. There are fixed frames and an annoying status bar, menu, message scroll, etc. I can see why they want a large fixed resolution.
Maybe I am just getting old.
(I also realize the reason for some of the new Web 2.0 stuff is for smaller devices like phones and hand-helds).