After reading this announcement, I decided to upgrade to 4.2 beta 1. Though I had been using nightly, but somebody advised me to go for the beta. Naturally, beta has all goodies of nightly (neon), but polished.
After the 135MB upgrade, here are a few basic observations.
Integration of Battery monitor with powerdevil
Lancelot comes by default
This is a great addition to the default widgets.
Systray icons look clean
System tray icons look good with no overlapping.
The zoom slider and better thumbnails
Dolphin shows good looking thumbnails with drop shadows, which can be viewed at a range of zoom levels using the zoom slider.
Previews in the folder view widget
Folder view now also allows selecting individual files with Ctrl + click. Very useful update.
“Examining” and “Transferring” notifications
I fail to understand the purpose of this notification daemon. I open an album in gwenview and keep pressing “Next” and it manages to drive me crazy 
Tooltips for plasma
KDE 4.2 has tooltips for plasma. What more, it that when you hover upon another plasma while a tooltip is displayed, the tooltip will gradually move towards the new plasma you are pointing to.
Additionally, you can rotate a plasma widget..
Overall, it’s a great package. Cheers to KDE developers!
I might be confused, but Neon never really gets stuff for me… not sure what’s the issue…
Anyway, upgraded to 4.2 recently and it looks very good.
Have a bug at time and desktop pretty much is replaced with a gnome desktop… friking weird.. oh well…
argh… seems i had to install kde-nightly and log into it’s session… heh
A Gnome desktop oO
I too had some dependency issues during install, but got them resolved. Happy since then
KDE 4.2 is great. I have occasional plasma crashes but thats okay!
Can I ask wich video card do you have?
An old Intel GMA900/915GM onboard (old laptop)