▶ NEW DESIGN Oct 2013 (after the last of dec 2012) :
Because this version is not updated, Use :
http://freestyler.ws/style/80156/yahoo-new-mail-simply-dark-and-gray-v-35

▶ The ScreenShot give a good idea of this beta, but is not really the final result.



▶ NEW To Remove right sidebar, keep message list as wide as browser window is Greasemonkey Script :
http://userscripts.org/scripts/show/170161
▶ Its Userstyles Version :
http://freestyler.ws/style/81826/yahoo-mail-wide-messages-list
▶ To delete the PUBS (eg, if you use Adblock, it always stay an empty space in the right column),
use this greasemonkey script:
http://userscripts.org/scripts/show/3115
But to use it , maybe , you needs to add new include for HTTPS (secure) connexions (read below)
▶ PARTICULARITY
(cf > : LAST changes):

>> (new11)
> SORT MAILS in MESSAGES LIST : : Horizontal menu, visible on a click on the TO SORT BAR /TRIER BARRE , to choose the item you want.
> FILE ICON in Message list : move to the left side.
> YAHOO MAIL CONFIGURATION PAGE : styled.

> HEADER: Corrections for Tabs/Header position and height, more compact, Reduce/Move elements, Supp Yahoo Logo, tiny Search Box etc...
- YAHOO SERVICES ICON : Not near The Reception Tab,
move to the Top/right of Search Block (like that we don't open always this yahoo popup )
> TOOLBAR/ NAV BAR : Move to the top(TRIPANE TOO),
> MENUS + POP UP MENU : More Infos in it , less scrolling... and Dark Gray, style Background/Border/separator, Hover, Selected items etc ...

- LEFT PANEL : Scrollable Custom Panels LIST, to just scroll it without move the entire page,
(when i want put a mail in a special folder by example)
- LEFT PANEL : Trash etc.. ICONS move , Numbers Mails, Label , Applications , etc... styled.

> CONTACTS PAGE : Many change, More readable, without the White Column on the right("theAd" !)

> CONTACTS EDITION : Many change, More readable and wide place to type your infos

- MAILS LIST : ZEBRA List, Icons readability/usability(Background), MAILS style for hover/Read/selected,
- MAILS LIST : TRASH Icon (move near OBJECT and STAR icon and replaced by a "X")

- MAIL READ/WRITE : Color , Wide Place to play(to read/write), wide contacts box, Color picker style
- MAIL WRITE (Choose CONTACT BOX) : Wide "Choose a Contact list"
- MAIL READ / WRITE Readability/usability : add intern scrollbar to scroll only the mail , not all the page.
- ICON FILE : move to the left side(before Expeditor)
> PUBS : Suppression
- Supp Publicity Column (Right Side Column : ("theAd" !))
and try to keep the width of the page at the max...



- TEST : support for the Preview under the messages list panel too
(without blank /white area around the toolbar).


== Last changes(new10) :
> GENERAL WIDTH : optimization (maybe usable for a more small sreen)
> BACKGROUND COLOR : many corrections
> TRIPANE : better style
> HEADER : more compact

> TABS + TOOLBAR : optimize position (for tripane too)
. APPLICATIONS PANEL (Messenger / Applications) : Styled
. ICONS USER Profile-LogOf / OPTIONS : Move to the Top
. YAHOO SERVICES ICON : Not near The Reception Tab,
move to the Top/right of Search Block (like that we don't open always this yahoo popup )
. SEARCH block : move to the Top/left

> MENUS + POPUP MENUS : Improve the style (Background, border, hover, selected items)
> MAILS : Improve Style
. MAILS LIST : Trash MAIL ICON move(to the left) near OBJECT and STAR icon and replaced by a "X"
> MAILS HEADER: move STAR(fav) + UN/READ ICONS to the left