The new spam and compose screen features are now available! For all the background on what they're about, see the discussions during their development:
http://www.emaildiscussions.com/...threadid=15708
http://www.emaildiscussions.com/...threadid=15778
We are gradually moving everyone over to the new spam screen - until your account is converted, you won't be able to change your spam threshold. It should be around 24 hours to convert everyone - you'll get an email at that time.
We'll be sending out a newsletter in the next day or two, about this and other stuff... We'll update the blog shortly...