Feature in Focus
Dash: "Shown on the left where your favorite applications and your running applications are shown. The glow behind the application icon indicates if the application is running."
Dash on the Bottom
Establishing symmetry between elements in visual design is important to make it feel more balanced. The Dash and the top Panel create this symmetry. The leading desktops and mobile interfaces also apply this principle. They put their own "Dash" at the bottom as well. This creates an archetype to follow that is common to most standard platforms. This will increase the efficiency of the desktop and make a more normal pattern to users coming to GNOME who are from platforms like Windows, Chrome OS, Android, Mac OS and many more.
When windows are minimized where do they go? They shouldn't go to the Dash because that will create clutter and be too busy. Instead the minimized windows should got the Message Tray. The location of the minimized apps in the Message Tray and the icons in the Dash, in the same relative location, will create further symmetry and balance. This should be aligned by a grid ideally.
This is also a great idea because when the user is in normal Desktop operation they can access their minimized windows with a quick flick of the mouse or a touchpad gesture. Clicking on the app icon should trigger some sort of windows list or a small window preview.
Comments: Microsoft calls this the Taskbar. By default it's located at the bottom of the screen and is integrated with the Start button and notification tray. The user is able to change the location of Taskbar at any time and can position it on the left or right or even the top of the screen if they choose to.
Reference: windows.microsoft.com "Windows 7 Taskbar"
Mac OS X
Comments: The Favorites Tray features a button in the middle, the grid icon, that is used to access the "All apps" screen where the user makes their selection. This is the Android version of the Dash. Even on this Linux based leading mobile platform the Dash is on the bottom to enhance symmetry.
Reference: developer.android.com "UI Overview"
Comments: It's interesting to see how the Android home screen and "Favorites Tray" looks when on larger mobile device such as the Nexus 10. In this view it's easy to see how such a screen would appear if it was on a desktop and could be compared side by side with Gnome Shell.
Any comments please tell!
SriramRamkrishna - I'm not sure you awnt to minimize the apps to the message area. It's not really designed for that and it's certainly not scalable. Once you grow past the number of windows, how will you scale it? Tech people will fill that table up, I've seen enough screenshots where people can have 20-30 terminals or web pages. It won't really work I feel.
The dash at the bottom could be workable, but being so close to the edge will trigger the message bar. This means that you have to be precise. I think that is not we want. We don't want to use too much precision, that's why the icons are a little bigger as well as for other reasons.
AlexGS - Scaling won't be an issue due to grouping by application. Windows 7 does this very elegantly as does Mac OS X. When there are multiple instances and windows of an application in the Dock or Taskbar it groups them by application. Simply right clicking pops open a list of those windows. In actual practice it's very difficult to open enough applications to exhaust that space when grouping is enabled.
Something clever could be done here with GNOME Shell as well. The thing I really like about having minimized windows go to the Message Tray is that the user can easily access these when they're in the Desktop view and thus it's a shortcut that saves time.