+1 skoelpin, add tab complete to my list of enhancement requests!
Changing the "skin" of splunk is done via css. I'm not aware of any apps for doing it... however, if you were to download 5.0, remove your search app, and then add the 5.0 app to 6.x... its not recommended, but I did prefer the view it gave. You could try just downloading 5.x and seeing if you like the UI or not. It would most likely cause some issues if you did the above, but nothing you couldnt work out if you're a developer.
This is pretty cool. The Visual SPL is a shell which will run SPL? Do you use it? Will this help debug queries or this is a "nice to have" thing where it gives the feeling of working in the shell?
I'm looking for a visual add-on which I can overlay ontop of our web interface to give it a better feel. Lastly, is there any add-ons I can use which will improve my Splunking efficiency (like tab complete)?