[glorify]

Like it, but maybe a bit too bulky for me with the scrolling.

What about showing the standard usernames in standard layout, and doing something like this in the thead:
Currently Active Users: 704 (193 members and 511 guests) Show Avatars
(When the link is clicked it shows avatars only with alt tags that show usernames)

and if avatars are selected:
Currently Active Users: 704 (193 members and 511 guests) Show User Names
(When the link is clicked it shows usernames only)

Obviously selected state remembered via cookie, and Admincp settings on:
Which way to show as default
What size avatars to display
Colums/Rows

Then someone can create a vbadvanced module that works the same way