Putting Applications/Windows in Top Sites-like array?

Do you mean Finder windows rather than application windows? If so, use the Cover Flow view. Otherwise, I guess I'm the dense one.

 

Expose' is pretty close for running applications.

I used to put my favorite apps into a folder in the doc, which did something close to what you are asking.

Create a new Folder "My Favorites"
Create Alias for the applciation you want to place in "My Favorites" (right click the App and select "Make Alias" - this is similar to creating a shortcut in Windows.
Drag the Alias to "My Favorites
Repeat for all of the apps you want to include
You can change the name of the alias just like any oter file - it still points to the original target
Now drag "My Faovorites" to the Dock. Change it's display properties to your liking - I prefer dispaly as Folder rather than Stack and I think that it about as close as you can get to the view you were asking about.

You may also want to just use "Recent Items" from the Apple Menu...

 

Spaces

While expose is a great way to see current windows, I really like the spaces feature. It allows you to have multiple desktops in a sense. You can assign a certain application to a certain space. ex) if you assign google chrome to space 2, than every time you open or switch to chrome, than it will automatically switch to space 2. I assign all my most-often used apps to certain spaces and it works great. Also assigning screen corner actions is useful. I assigned a screen corner to activate spaces.

 

Ok, if I'm understanding you now: No. That would be asking different applications to "play nice" with each other. Much easier to do that within one application, like Finder.

You can Command-Tab to "scroll through" open applications. Were you aware of that?