Maxaud

(NOTE: Before saying this plugin is broken, please understand what this plugin does. It’s meant for WordPress installs that have multiple NETWORKS.)
Adds the ability to have different themes available to different NETWORKS in a multisite atmoshpere.
WordPress allows for multiple “networks”, these are not to be confused with sites. A network holds blogs underneath of it.
This plugin will allow you to separate themes into different directories so they’re only accessable and viewable to the networks you choose.
The plugin will attempt to create a directory in the /wp-content/ directory named /ms-themes/. If it fails to create it, then you will need to make one.
In the /ms-themes/ directory you will create a folder for each network that you want to allow only certain themes to.
Example: 
If you have a theme named “Snarfer Theme”, and you want to only allow it to be viewable/available to the network (and all sites on that network) with the site_id of 7, you would place the snarfer theme directory in /wp-content/ms-themes/7/
Future releases:
<ul>
<li>Network option to turn off auto creation on/off network directories, index.php files.</li>
<li>Network option to display network ID in the footer of sites so network admins can easily tell what network a site is under.</li>
</ul>

Multisite Themes

Adds the ability to have different themes available to different NETWORKS in a multisite atmoshpere.

erikshosting

Are you trying to customize your WordPress Dashboard across ALL wpmu or wp3 Multi-Site blog networks?
Remove ALL WordPress Dashboard Widgets! Network Activate To Use Network Wide!
What This Plugin Offers!: 
Configure Once! Network Wide! 
Remove ALL default dashboard widgets! 
WP3+ & BP 1.2+ Compatible!
Why Use This Over Other Dash Widget Removal Plugins?: 
Most of the Plugin Solutions are on a per-blog basis, no sitewide configuration!
Existing solutions do not remove ALL dashboard widgets!
<h3>Features</h3>
Configure Once! Network Wide! 
Remove ALL default dashboard widgets! 
WP3+ & BP 1.2+ Compatible!
<h3>Coming In Future Versions</h3>

Dashboard Widgets Network Removal

Remove All Dashboard Widgets In Single WP, Or Multi-Site!

Multisite Themes vs Dashboard Widgets Network Removal